81762681 has 64 divisors (see below), whose sum is σ = 154183680. Its totient is φ = 37117440.

The previous prime is 81762679. The next prime is 81762691. The reversal of 81762681 is 18626718.

It is not a de Polignac number, because 81762681 - 2¹ = 81762679 is a prime.

It is a super-2 number, since 2×81762681² = 13370272008615522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (81762671) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 56341 + ... + 57773.

It is an arithmetic number, because the mean of its divisors is an integer number (2409120).

Almost surely, 2^81762681 is an apocalyptic number.

It is an amenable number.

81762681 is a deficient number, since it is larger than the sum of its proper divisors (72420999).

81762681 is a wasteful number, since it uses less digits than its factorization.

81762681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1486.

The product of its digits is 32256, while the sum is 39.

The square root of 81762681 is about 9042.2718937223. The cubic root of 81762681 is about 434.0286265246.

The spelling of 81762681 in words is "eighty-one million, seven hundred sixty-two thousand, six hundred eighty-one".