81051264 has 288 divisors, whose sum is σ = 293311200. Its totient is φ = 20984832.

The previous prime is 81051251. The next prime is 81051277. The reversal of 81051264 is 46215018.

It is an interprime number because it is at equal distance from previous prime (81051251) and next prime (81051277).

It is a tau number, because it is divible by the number of its divisors (288).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3523957 + ... + 3523979.

Almost surely, 2^81051264 is an apocalyptic number.

81051264 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81051264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146655600).

81051264 is an abundant number, since it is smaller than the sum of its proper divisors (212259936).

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

81051264 is a wasteful number, since it uses less digits than its factorization.

81051264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 81051264 is about 9002.8475495256. The cubic root of 81051264 is about 432.7661302154.

The spelling of 81051264 in words is "eighty-one million, fifty-one thousand, two hundred sixty-four".