1213620 has 48 divisors (see below), whose sum is σ = 3447360. Its totient is φ = 318976.

The previous prime is 1213607. The next prime is 1213627. The reversal of 1213620 is 263121.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1213620.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213627) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6691 + ... + 6869.

It is an arithmetic number, because the mean of its divisors is an integer number (71820).

2^1213620 is an apocalyptic number.

1213620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1213620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1723680).

1213620 is an abundant number, since it is smaller than the sum of its proper divisors (2233740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1213620 is a wasteful number, since it uses less digits than its factorization.

1213620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 302 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1213620 is about 1101.6442256918. The cubic root of 1213620 is about 106.6663845479. Note that the first 3 decimals are identical.

1213620 divided by its sum of digits (15) gives a palindrome (80908).

Adding to 1213620 its reverse (263121), we get a palindrome (1476741).

It can be divided in two parts, 121 and 3620, that added together give a triangular number (3741 = T₈₆).

The spelling of 1213620 in words is "one million, two hundred thirteen thousand, six hundred twenty".