81507190 has 16 divisors (see below), whose sum is σ = 147412080. Its totient is φ = 32447520.

The previous prime is 81507187. The next prime is 81507211. The reversal of 81507190 is 9170518.

It is a super-2 number, since 2×81507190² = 13286844043392200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17205 + ... + 21424.

It is an arithmetic number, because the mean of its divisors is an integer number (9213255).

Almost surely, 2^81507190 is an apocalyptic number.

81507190 is a deficient number, since it is larger than the sum of its proper divisors (65904890).

81507190 is a wasteful number, since it uses less digits than its factorization.

81507190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38847.

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 81507190 is about 9028.1332511212. The cubic root of 81507190 is about 433.5760724157.

The spelling of 81507190 in words is "eighty-one million, five hundred seven thousand, one hundred ninety".