61725978911 has 2 divisors, whose sum is σ = 61725978912. Its totient is φ = 61725978910.

The previous prime is 61725978893. The next prime is 61725978917. The reversal of 61725978911 is 11987952716.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61725978911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61725978917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30862989455 + 30862989456.

It is an arithmetic number, because the mean of its divisors is an integer number (30862989456).

Almost surely, 2^61725978911 is an apocalyptic number.

61725978911 is a deficient number, since it is larger than the sum of its proper divisors (1).

61725978911 is an equidigital number, since it uses as much as digits as its factorization.

61725978911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1905120, while the sum is 56.

The spelling of 61725978911 in words is "sixty-one billion, seven hundred twenty-five million, nine hundred seventy-eight thousand, nine hundred eleven".