81501807 has 16 divisors (see below), whose sum is σ = 112020480. Its totient is φ = 52680672.

The previous prime is 81501779. The next prime is 81501881. The reversal of 81501807 is 70810518.

It is not a de Polignac number, because 81501807 - 2¹⁴ = 81485423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81505807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12718 + ... + 18020.

It is an arithmetic number, because the mean of its divisors is an integer number (7001280).

Almost surely, 2^81501807 is an apocalyptic number.

81501807 is a deficient number, since it is larger than the sum of its proper divisors (30518673).

81501807 is a wasteful number, since it uses less digits than its factorization.

81501807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5462.

The product of its (nonzero) digits is 2240, while the sum is 30.

The square root of 81501807 is about 9027.8351225529. The cubic root of 81501807 is about 433.5665272807.

The spelling of 81501807 in words is "eighty-one million, five hundred one thousand, eight hundred seven".