81001954 has 32 divisors (see below), whose sum is σ = 137106432. Its totient is φ = 35568000.

The previous prime is 81001931. The next prime is 81001979. The reversal of 81001954 is 45910018.

It is a happy number.

It is a super-2 number, since 2×81001954² = 13122633103636232, which contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 155214 + ... + 155734.

It is an arithmetic number, because the mean of its divisors is an integer number (4284576).

Almost surely, 2^81001954 is an apocalyptic number.

81001954 is a deficient number, since it is larger than the sum of its proper divisors (56104478).

81001954 is a wasteful number, since it uses less digits than its factorization.

81001954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 762.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 81001954 is about 9000.1085549009. The cubic root of 81001954 is about 432.6783502688.

The spelling of 81001954 in words is "eighty-one million, one thousand, nine hundred fifty-four".