81501837 has 8 divisors (see below), whose sum is σ = 108908736. Its totient is φ = 54214752.

The previous prime is 81501779. The next prime is 81501881. The reversal of 81501837 is 73810518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81501837 - 2⁷ = 81501709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81501798 and 81501807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81506837) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28353 + ... + 31094.

It is an arithmetic number, because the mean of its divisors is an integer number (13613592).

Almost surely, 2^81501837 is an apocalyptic number.

It is an amenable number.

81501837 is a deficient number, since it is larger than the sum of its proper divisors (27406899).

81501837 is a wasteful number, since it uses less digits than its factorization.

81501837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59907.

The product of its (nonzero) digits is 6720, while the sum is 33.

The square root of 81501837 is about 9027.8367840807. The cubic root of 81501837 is about 433.5665804779.

The spelling of 81501837 in words is "eighty-one million, five hundred one thousand, eight hundred thirty-seven".