81121974 has 12 divisors (see below), whose sum is σ = 162288084. Its totient is φ = 27033304.

The previous prime is 81121967. The next prime is 81121981. The reversal of 81121974 is 47912118.

It is an interprime number because it is at equal distance from previous prime (81121967) and next prime (81121981).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 20224 + ... + 23900.

It is an arithmetic number, because the mean of its divisors is an integer number (13524007).

Almost surely, 2^81121974 is an apocalyptic number.

81121974 is an abundant number, since it is smaller than the sum of its proper divisors (81166110).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81121974 is an frugal number, since it uses more digits than its factorization.

81121974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7359 (or 3682 counting only the distinct ones).

The product of its digits is 4032, while the sum is 33.

The square root of 81121974 is about 9006.7737842137. The cubic root of 81121974 is about 432.8919435876.

The spelling of 81121974 in words is "eighty-one million, one hundred twenty-one thousand, nine hundred seventy-four".