997021620 has 108 divisors (see below), whose sum is σ = 3518093124. Its totient is φ = 227888640.

The previous prime is 997021609. The next prime is 997021639. The reversal of 997021620 is 26120799.

997021620 is a `hidden beast` number, since 9 + 9 + 7 + 0 + 21 + 620 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 518199696 + 478821924 = 22764^2 + 21882^2 .

It is a super-2 number, since 2×997021620² = 1988104221494848800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 47701 + ... + 65340.

Almost surely, 2^997021620 is an apocalyptic number.

997021620 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

997021620 is an abundant number, since it is smaller than the sum of its proper divisors (2521071504).

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

997021620 is a wasteful number, since it uses less digits than its factorization.

997021620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113070 (or 113058 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 997021620 is about 31575.6491619729. The cubic root of 997021620 is about 999.0062193939.

The spelling of 997021620 in words is "nine hundred ninety-seven million, twenty-one thousand, six hundred twenty".