61661731 has 2 divisors, whose sum is σ = 61661732. Its totient is φ = 61661730.

The previous prime is 61661723. The next prime is 61661773. The reversal of 61661731 is 13716616.

61661731 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61661731 - 2³ = 61661723 is a prime.

It is a super-2 number, since 2×61661731² = 7604338139832722, which contains 22 as substring.

It is equal to p_3654742 and since 61661731 and 3654742 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 61661693 and 61661702.

It is not a weakly prime, because it can be changed into another prime (61661231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30830865 + 30830866.

It is an arithmetic number, because the mean of its divisors is an integer number (30830866).

Almost surely, 2^61661731 is an apocalyptic number.

61661731 is a deficient number, since it is larger than the sum of its proper divisors (1).

61661731 is an equidigital number, since it uses as much as digits as its factorization.

61661731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 31.

The square root of 61661731 is about 7852.4983922316. The cubic root of 61661731 is about 395.0680457467.

The spelling of 61661731 in words is "sixty-one million, six hundred sixty-one thousand, seven hundred thirty-one".