61979791 has 2 divisors, whose sum is σ = 61979792. Its totient is φ = 61979790.

The previous prime is 61979789. The next prime is 61979803. The reversal of 61979791 is 19797916.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61979791 - 2¹ = 61979789 is a prime.

Together with 61979789, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61979591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30989895 + 30989896.

It is an arithmetic number, because the mean of its divisors is an integer number (30989896).

Almost surely, 2^61979791 is an apocalyptic number.

61979791 is a deficient number, since it is larger than the sum of its proper divisors (1).

61979791 is an equidigital number, since it uses as much as digits as its factorization.

61979791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 214326, while the sum is 49.

The square root of 61979791 is about 7872.7244966403. The cubic root of 61979791 is about 395.7461535898.

The spelling of 61979791 in words is "sixty-one million, nine hundred seventy-nine thousand, seven hundred ninety-one".