81551954 has 16 divisors (see below), whose sum is σ = 134472096. Its totient is φ = 36784800.

The previous prime is 81551927. The next prime is 81551969. The reversal of 81551954 is 45915518.

It is a Curzon 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, 11267 + ... + 17030.

It is an arithmetic number, because the mean of its divisors is an integer number (8404506).

Almost surely, 2^81551954 is an apocalyptic number.

81551954 is a deficient number, since it is larger than the sum of its proper divisors (52920142).

81551954 is a wasteful number, since it uses less digits than its factorization.

81551954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28441.

The product of its digits is 36000, while the sum is 38.

The square root of 81551954 is about 9030.6120501326. The cubic root of 81551954 is about 433.6554316612.

The spelling of 81551954 in words is "eighty-one million, five hundred fifty-one thousand, nine hundred fifty-four".