97661989 has 8 divisors (see below), whose sum is σ = 98470008. Its totient is φ = 96857280.

The previous prime is 97661953. The next prime is 97661999. The reversal of 97661989 is 98916679.

It can be written as a sum of positive squares in 4 ways, for example, as 14760964 + 82901025 = 3842^2 + 9105^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 97661989 - 2²⁵ = 64107557 is a prime.

It is a super-2 number, since 2×97661989² = 19075728190872242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97661909) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122139 + ... + 122935.

It is an arithmetic number, because the mean of its divisors is an integer number (12308751).

Almost surely, 2^97661989 is an apocalyptic number.

It is an amenable number.

97661989 is a deficient number, since it is larger than the sum of its proper divisors (808019).

97661989 is a wasteful number, since it uses less digits than its factorization.

97661989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1655.

The product of its digits is 1469664, while the sum is 55.

The square root of 97661989 is about 9882.4080567441. The cubic root of 97661989 is about 460.5129580202.

The spelling of 97661989 in words is "ninety-seven million, six hundred sixty-one thousand, nine hundred eighty-nine".