97990861 has 4 divisors (see below), whose sum is σ = 100380924. Its totient is φ = 95600800.

The previous prime is 97990859. The next prime is 97990901. The reversal of 97990861 is 16809979.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20884900 + 77105961 = 4570^2 + 8781^2 .

It is a cyclic number.

It is not a de Polignac number, because 97990861 - 2¹ = 97990859 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97990811) 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, 1194970 + ... + 1195051.

It is an arithmetic number, because the mean of its divisors is an integer number (25095231).

Almost surely, 2^97990861 is an apocalyptic number.

It is an amenable number.

97990861 is a deficient number, since it is larger than the sum of its proper divisors (2390063).

97990861 is a wasteful number, since it uses less digits than its factorization.

97990861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2390062.

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 97990861 is about 9899.0333366445. The cubic root of 97990861 is about 461.0292972034.

The spelling of 97990861 in words is "ninety-seven million, nine hundred ninety thousand, eight hundred sixty-one".