81880947 has 6 divisors (see below), whose sum is σ = 118272492. Its totient is φ = 54587292.

The previous prime is 81880933. The next prime is 81880957. The reversal of 81880947 is 74908818.

It is not a de Polignac number, because 81880947 - 2⁷ = 81880819 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81880957) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4548933 + ... + 4548950.

It is an arithmetic number, because the mean of its divisors is an integer number (19712082).

Almost surely, 2^81880947 is an apocalyptic number.

81880947 is a deficient number, since it is larger than the sum of its proper divisors (36391545).

81880947 is a wasteful number, since it uses less digits than its factorization.

81880947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9097889 (or 9097886 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The square root of 81880947 is about 9048.8091481697. The cubic root of 81880947 is about 434.2377932641.

The spelling of 81880947 in words is "eighty-one million, eight hundred eighty thousand, nine hundred forty-seven".