1021620 has 24 divisors (see below), whose sum is σ = 2860704. Its totient is φ = 272416.

The previous prime is 1021577. The next prime is 1021621. The reversal of 1021620 is 261201.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1021596 and 1021605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021621) 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, 8454 + ... + 8573.

It is an arithmetic number, because the mean of its divisors is an integer number (119196).

2^1021620 is an apocalyptic number.

1021620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021620 is an abundant number, since it is smaller than the sum of its proper divisors (1839084).

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

1021620 is a wasteful number, since it uses less digits than its factorization.

1021620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17039 (or 17037 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 1021620 is about 1010.7521951497. The cubic root of 1021620 is about 100.7155345581.

Adding to 1021620 its reverse (261201), we get a palindrome (1282821).

The spelling of 1021620 in words is "one million, twenty-one thousand, six hundred twenty".