81006772 has 24 divisors (see below), whose sum is σ = 176742720. Its totient is φ = 31560960.

The previous prime is 81006767. The next prime is 81006781. The reversal of 81006772 is 27760018.

It is a happy number.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131197 + ... + 131812.

It is an arithmetic number, because the mean of its divisors is an integer number (7364280).

Almost surely, 2^81006772 is an apocalyptic number.

It is an amenable number.

81006772 is an abundant number, since it is smaller than the sum of its proper divisors (95735948).

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

81006772 is a wasteful number, since it uses less digits than its factorization.

81006772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263031 (or 263029 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 81006772 is about 9000.3762143590. The cubic root of 81006772 is about 432.6869286748.

The spelling of 81006772 in words is "eighty-one million, six thousand, seven hundred seventy-two".