76213721 has 2 divisors, whose sum is σ = 76213722. Its totient is φ = 76213720.

The previous prime is 76213699. The next prime is 76213723. The reversal of 76213721 is 12731267.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59892121 + 16321600 = 7739^2 + 4040^2 .

It is a cyclic number.

It is not a de Polignac number, because 76213721 - 2¹⁴ = 76197337 is a prime.

Together with 76213723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (76213723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38106860 + 38106861.

It is an arithmetic number, because the mean of its divisors is an integer number (38106861).

Almost surely, 2^76213721 is an apocalyptic number.

It is an amenable number.

76213721 is a deficient number, since it is larger than the sum of its proper divisors (1).

76213721 is an equidigital number, since it uses as much as digits as its factorization.

76213721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3528, while the sum is 29.

The square root of 76213721 is about 8730.0470216374. The cubic root of 76213721 is about 423.9790414020.

Adding to 76213721 its reverse (12731267), we get a palindrome (88944988).

The spelling of 76213721 in words is "seventy-six million, two hundred thirteen thousand, seven hundred twenty-one".