81935590 has 32 divisors (see below), whose sum is σ = 162095904. Its totient is φ = 29571840.

The previous prime is 81935587. The next prime is 81935593. The reversal of 81935590 is 9553918.

It is an interprime number because it is at equal distance from previous prime (81935587) and next prime (81935593).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81935593) 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, 12352 + ... + 17788.

It is an arithmetic number, because the mean of its divisors is an integer number (5065497).

Almost surely, 2^81935590 is an apocalyptic number.

81935590 is a deficient number, since it is larger than the sum of its proper divisors (80160314).

81935590 is a wasteful number, since it uses less digits than its factorization.

81935590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5592.

The product of its (nonzero) digits is 48600, while the sum is 40.

The square root of 81935590 is about 9051.8279921793. The cubic root of 81935590 is about 434.3343675396.

The spelling of 81935590 in words is "eighty-one million, nine hundred thirty-five thousand, five hundred ninety".