76881221 has 2 divisors, whose sum is σ = 76881222. Its totient is φ = 76881220.

The previous prime is 76881187. The next prime is 76881241. The reversal of 76881221 is 12218867.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43692100 + 33189121 = 6610^2 + 5761^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-76881221 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (76881241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38440610 + 38440611.

It is an arithmetic number, because the mean of its divisors is an integer number (38440611).

Almost surely, 2^76881221 is an apocalyptic number.

It is an amenable number.

76881221 is a deficient number, since it is larger than the sum of its proper divisors (1).

76881221 is an equidigital number, since it uses as much as digits as its factorization.

76881221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 35.

The square root of 76881221 is about 8768.1937136448. The cubic root of 76881221 is about 425.2132189635.

The spelling of 76881221 in words is "seventy-six million, eight hundred eighty-one thousand, two hundred twenty-one".