81876501 has 50 divisors (see below), whose sum is σ = 143024662. Its totient is φ = 46675440.

The previous prime is 81876499. The next prime is 81876551. The reversal of 81876501 is 10567818.

81876501 is a `hidden beast` number, since 81 + 8 + 76 + 501 = 666.

It can be written as a sum of positive squares in only one way, i.e., 43758225 + 38118276 = 6615^2 + 6174^2 .

It is not a de Polignac number, because 81876501 - 2¹ = 81876499 is a prime.

It is a super-2 number, since 2×81876501² = 13407522832006002, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81876551) by changing a digit.

It is a polite number, since it can be written in 49 ways as a sum of consecutive naturals, for example, 194271 + ... + 194691.

Almost surely, 2^81876501 is an apocalyptic number.

81876501 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

81876501 is a deficient number, since it is larger than the sum of its proper divisors (61148161).

81876501 is an frugal number, since it uses more digits than its factorization.

81876501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461 (or 431 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 36.

The square root of 81876501 is about 9048.5634771493. The cubic root of 81876501 is about 434.2299336571.

The spelling of 81876501 in words is "eighty-one million, eight hundred seventy-six thousand, five hundred one".