66157631 has 2 divisors, whose sum is σ = 66157632. Its totient is φ = 66157630.

The previous prime is 66157571. The next prime is 66157657. The reversal of 66157631 is 13675166.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66157631 - 2¹⁴ = 66141247 is a prime.

It is a super-2 number, since 2×66157631² = 8753664279064322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 66157591 and 66157600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66157661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33078815 + 33078816.

It is an arithmetic number, because the mean of its divisors is an integer number (33078816).

Almost surely, 2^66157631 is an apocalyptic number.

66157631 is a deficient number, since it is larger than the sum of its proper divisors (1).

66157631 is an equidigital number, since it uses as much as digits as its factorization.

66157631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 35.

The square root of 66157631 is about 8133.7341362993. The cubic root of 66157631 is about 404.4454759167.

The spelling of 66157631 in words is "sixty-six million, one hundred fifty-seven thousand, six hundred thirty-one".