397802097921621 has 32 divisors (see below), whose sum is σ = 543405041827200. Its totient is φ = 258802871463936.

The previous prime is 397802097921607. The next prime is 397802097921707. The reversal of 397802097921621 is 126129790208793.

It is a happy number.

It is not a de Polignac number, because 397802097921621 - 2²⁵ = 397802064367189 is a prime.

It is a super-2 number, since 2×397802097921621² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397802097921721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27543811 + ... + 39424176.

It is an arithmetic number, because the mean of its divisors is an integer number (16981407557100).

Almost surely, 2^{397802097921621} is an apocalyptic number.

It is an amenable number.

397802097921621 is a deficient number, since it is larger than the sum of its proper divisors (145602943905579).

397802097921621 is a wasteful number, since it uses less digits than its factorization.

397802097921621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66968373.

The product of its (nonzero) digits is 41150592, while the sum is 66.

The spelling of 397802097921621 in words is "three hundred ninety-seven trillion, eight hundred two billion, ninety-seven million, nine hundred twenty-one thousand, six hundred twenty-one".