1521220 has 24 divisors (see below), whose sum is σ = 3334464. Its totient is φ = 581856.

The previous prime is 1521217. The next prime is 1521227. The reversal of 1521220 is 221251.

It is a super-2 number, since 2×1521220² = 4628220576800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1521220.

It is not an unprimeable number, because it can be changed into a prime (1521227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1194 + ... + 2113.

It is an arithmetic number, because the mean of its divisors is an integer number (138936).

2^1521220 is an apocalyptic number.

1521220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1521220 is an abundant number, since it is smaller than the sum of its proper divisors (1813244).

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

1521220 is a wasteful number, since it uses less digits than its factorization.

1521220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3339 (or 3337 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 1521220 is about 1233.3774766875. The cubic root of 1521220 is about 115.0086949947.

Adding to 1521220 its reverse (221251), we get a palindrome (1742471).

The spelling of 1521220 in words is "one million, five hundred twenty-one thousand, two hundred twenty".