76220721 has 12 divisors (see below), whose sum is σ = 111166848. Its totient is φ = 50319864.

The previous prime is 76220719. The next prime is 76220759. The reversal of 76220721 is 12702267.

It is not a de Polignac number, because 76220721 - 2¹ = 76220719 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (76220791) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40185 + ... + 42038.

It is an arithmetic number, because the mean of its divisors is an integer number (9263904).

Almost surely, 2^76220721 is an apocalyptic number.

It is an amenable number.

76220721 is a deficient number, since it is larger than the sum of its proper divisors (34946127).

76220721 is a wasteful number, since it uses less digits than its factorization.

76220721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82332 (or 82329 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 76220721 is about 8730.4479266530. The cubic root of 76220721 is about 423.9920214026.

Adding to 76220721 its reverse (12702267), we get a palindrome (88922988).

The spelling of 76220721 in words is "seventy-six million, two hundred twenty thousand, seven hundred twenty-one".