81400632 has 16 divisors (see below), whose sum is σ = 203501640. Its totient is φ = 27133536.

The previous prime is 81400603. The next prime is 81400661. The reversal of 81400632 is 23600418.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81400603) and next prime (81400661).

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 3391693 = 81400632 / (8 + 1 + 4 + 0 + 0 + 6 + 3 + 2).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1695823 + ... + 1695870.

Almost surely, 2^81400632 is an apocalyptic number.

It is an amenable number.

81400632 is an abundant number, since it is smaller than the sum of its proper divisors (122101008).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81400632 is a wasteful number, since it uses less digits than its factorization.

81400632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3391702 (or 3391698 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 81400632 is about 9022.2298795808. The cubic root of 81400632 is about 433.3870455445.

The spelling of 81400632 in words is "eighty-one million, four hundred thousand, six hundred thirty-two".