76921 has 8 divisors (see below), whose sum is σ = 85064. Its totient is φ = 69120.

The previous prime is 76919. The next prime is 76943. The reversal of 76921 is 12967.

It can be written as a sum of positive squares in 4 ways, for example, as 1296 + 75625 = 36^2 + 275^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 3-Lehmer number, since φ(76921) divides (76921-1)³.

It is a cyclic number.

It is not a de Polignac number, because 76921 - 2¹ = 76919 is a prime.

It is an Ulam number.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76961) 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, 745 + ... + 841.

It is an arithmetic number, because the mean of its divisors is an integer number (10633).

2⁷⁶⁹²¹ is an apocalyptic number.

It is an amenable number.

76921 is a deficient number, since it is larger than the sum of its proper divisors (8143).

76921 is a wasteful number, since it uses less digits than its factorization.

76921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171.

The product of its digits is 756, while the sum is 25.

The square root of 76921 is about 277.3463538610. The cubic root of 76921 is about 42.5286542635.

Adding to 76921 its product of digits (756), we get a palindrome (77677).

It can be divided in two parts, 76 and 921, that multiplied together give a palindrome (69996).

The spelling of 76921 in words is "seventy-six thousand, nine hundred twenty-one".