81177970 has 16 divisors (see below), whose sum is σ = 146223000. Its totient is φ = 32448384.

The previous prime is 81177961. The next prime is 81177973. The reversal of 81177970 is 7977118.

It can be written as a sum of positive squares in 4 ways, for example, as 61826769 + 19351201 = 7863^2 + 4399^2 .

It is not an unprimeable number, because it can be changed into a prime (81177973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26014 + ... + 28966.

Almost surely, 2^81177970 is an apocalyptic number.

81177970 is a deficient number, since it is larger than the sum of its proper divisors (65045030).

81177970 is a wasteful number, since it uses less digits than its factorization.

81177970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5709.

The product of its (nonzero) digits is 24696, while the sum is 40.

The square root of 81177970 is about 9009.8817972269. The cubic root of 81177970 is about 432.9915246702.

The spelling of 81177970 in words is "eighty-one million, one hundred seventy-seven thousand, nine hundred seventy".