88631981 has 2 divisors, whose sum is σ = 88631982. Its totient is φ = 88631980.

The previous prime is 88631971. The next prime is 88631993. The reversal of 88631981 is 18913688.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67158025 + 21473956 = 8195^2 + 4634^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-88631981 is a prime.

It is a super-2 number, since 2×88631981² = 15711256111968722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (88631911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 44315990 + 44315991.

It is an arithmetic number, because the mean of its divisors is an integer number (44315991).

Almost surely, 2^88631981 is an apocalyptic number.

It is an amenable number.

88631981 is a deficient number, since it is larger than the sum of its proper divisors (1).

88631981 is an equidigital number, since it uses as much as digits as its factorization.

88631981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 44.

The square root of 88631981 is about 9414.4559587902. The cubic root of 88631981 is about 445.8582619848.

The spelling of 88631981 in words is "eighty-eight million, six hundred thirty-one thousand, nine hundred eighty-one".