97991022021 has 4 divisors (see below), whose sum is σ = 130654696032. Its totient is φ = 65327348012.

The previous prime is 97991022001. The next prime is 97991022023. The reversal of 97991022021 is 12022019979.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 97991022021 - 2⁷ = 97991021893 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97991022023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16331837001 + ... + 16331837006.

It is an arithmetic number, because the mean of its divisors is an integer number (32663674008).

Almost surely, 2^97991022021 is an apocalyptic number.

It is an amenable number.

97991022021 is a deficient number, since it is larger than the sum of its proper divisors (32663674011).

97991022021 is a wasteful number, since it uses less digits than its factorization.

97991022021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32663674010.

The product of its (nonzero) digits is 40824, while the sum is 42.

The spelling of 97991022021 in words is "ninety-seven billion, nine hundred ninety-one million, twenty-two thousand, twenty-one".