81018464 has 24 divisors (see below), whose sum is σ = 168888888. Its totient is φ = 38126080.

The previous prime is 81018449. The next prime is 81018467. The reversal of 81018464 is 46481018.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a self number, because there is not a number n which added to its sum of digits gives 81018464.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81018467) 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, 73922 + ... + 75009.

It is an arithmetic number, because the mean of its divisors is an integer number (7037037).

Almost surely, 2^81018464 is an apocalyptic number.

It is an amenable number.

81018464 is an abundant number, since it is smaller than the sum of its proper divisors (87870424).

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

81018464 is a wasteful number, since it uses less digits than its factorization.

81018464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148958 (or 148950 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 81018464 is about 9001.0257193278. The cubic root of 81018464 is about 432.7077447625.

The spelling of 81018464 in words is "eighty-one million, eighteen thousand, four hundred sixty-four".