61157639 has 2 divisors, whose sum is σ = 61157640. Its totient is φ = 61157638.

The previous prime is 61157617. The next prime is 61157641. The reversal of 61157639 is 93675116.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61157639 is a prime.

Together with 61157641, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61157039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30578819 + 30578820.

It is an arithmetic number, because the mean of its divisors is an integer number (30578820).

Almost surely, 2^61157639 is an apocalyptic number.

61157639 is a deficient number, since it is larger than the sum of its proper divisors (1).

61157639 is an equidigital number, since it uses as much as digits as its factorization.

61157639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34020, while the sum is 38.

The square root of 61157639 is about 7820.3349672504. The cubic root of 61157639 is about 393.9885225169.

The spelling of 61157639 in words is "sixty-one million, one hundred fifty-seven thousand, six hundred thirty-nine".