77215157 has 2 divisors, whose sum is σ = 77215158. Its totient is φ = 77215156.

The previous prime is 77215133. The next prime is 77215211. The reversal of 77215157 is 75151277.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72012196 + 5202961 = 8486^2 + 2281^2 .

It is a cyclic number.

It is not a de Polignac number, because 77215157 - 2¹⁸ = 76953013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77215657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38607578 + 38607579.

It is an arithmetic number, because the mean of its divisors is an integer number (38607579).

Almost surely, 2^77215157 is an apocalyptic number.

It is an amenable number.

77215157 is a deficient number, since it is larger than the sum of its proper divisors (1).

77215157 is an equidigital number, since it uses as much as digits as its factorization.

77215157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17150, while the sum is 35.

The square root of 77215157 is about 8787.2155430489. The cubic root of 77215157 is about 425.8279720816.

The spelling of 77215157 in words is "seventy-seven million, two hundred fifteen thousand, one hundred fifty-seven".