86697981 has 6 divisors (see below), whose sum is σ = 125230430. Its totient is φ = 57798648.

The previous prime is 86697973. The next prime is 86697991. The reversal of 86697981 is 18979668.

It can be written as a sum of positive squares in only one way, i.e., 46172025 + 40525956 = 6795^2 + 6366^2 .

It is not a de Polignac number, because 86697981 - 2³ = 86697973 is a prime.

It is a super-2 number, since 2×86697981² = 15033079818952722, 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 (86697901) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4816546 + ... + 4816563.

Almost surely, 2^86697981 is an apocalyptic number.

It is an amenable number.

86697981 is a deficient number, since it is larger than the sum of its proper divisors (38532449).

86697981 is a wasteful number, since it uses less digits than its factorization.

86697981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9633115 (or 9633112 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The square root of 86697981 is about 9311.1750601092. The cubic root of 86697981 is about 442.5914241816.

It can be divided in two parts, 86697 and 981, that added together give a palindrome (87678).

The spelling of 86697981 in words is "eighty-six million, six hundred ninety-seven thousand, nine hundred eighty-one".