97978690 has 8 divisors (see below), whose sum is σ = 176361660. Its totient is φ = 39191472.

The previous prime is 97978663. The next prime is 97978697. The reversal of 97978690 is 9687979.

It can be written as a sum of positive squares in 2 ways, for example, as 83302129 + 14676561 = 9127^2 + 3831^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×97978690² = 19199647388232200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (97978697) 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, 4898925 + ... + 4898944.

Almost surely, 2^97978690 is an apocalyptic number.

97978690 is a deficient number, since it is larger than the sum of its proper divisors (78382970).

97978690 is a wasteful number, since it uses less digits than its factorization.

97978690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9797876.

The product of its (nonzero) digits is 1714608, while the sum is 55.

The square root of 97978690 is about 9898.4185605580. The cubic root of 97978690 is about 461.0102089611.

The spelling of 97978690 in words is "ninety-seven million, nine hundred seventy-eight thousand, six hundred ninety".