61931491 has 2 divisors, whose sum is σ = 61931492. Its totient is φ = 61931490.

The previous prime is 61931461. The next prime is 61931537. The reversal of 61931491 is 19413916.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61931491 - 2¹⁷ = 61800419 is a prime.

It is not a weakly prime, because it can be changed into another prime (61931461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30965745 + 30965746.

It is an arithmetic number, because the mean of its divisors is an integer number (30965746).

Almost surely, 2^61931491 is an apocalyptic number.

61931491 is a deficient number, since it is larger than the sum of its proper divisors (1).

61931491 is an equidigital number, since it uses as much as digits as its factorization.

61931491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 34.

The square root of 61931491 is about 7869.6563457371. The cubic root of 61931491 is about 395.6433270271.

The spelling of 61931491 in words is "sixty-one million, nine hundred thirty-one thousand, four hundred ninety-one".