97777661 has 4 divisors (see below), whose sum is σ = 100162524. Its totient is φ = 95392800.

The previous prime is 97777621. The next prime is 97777663. The reversal of 97777661 is 16677779.

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 9060100 + 88717561 = 3010^2 + 9419^2 .

It is a cyclic number.

It is not a de Polignac number, because 97777661 - 2²⁶ = 30668797 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97777663) 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, 1192370 + ... + 1192451.

It is an arithmetic number, because the mean of its divisors is an integer number (25040631).

Almost surely, 2^97777661 is an apocalyptic number.

It is an amenable number.

97777661 is a deficient number, since it is larger than the sum of its proper divisors (2384863).

97777661 is a wasteful number, since it uses less digits than its factorization.

97777661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2384862.

The product of its digits is 777924, while the sum is 50.

The square root of 97777661 is about 9888.2587445920. The cubic root of 97777661 is about 460.6946985952.

The spelling of 97777661 in words is "ninety-seven million, seven hundred seventy-seven thousand, six hundred sixty-one".