61317921 has 32 divisors (see below), whose sum is σ = 98933760. Its totient is φ = 32999616.

The previous prime is 61317899. The next prime is 61317923. The reversal of 61317921 is 12971316.

61317921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61317921 - 2⁵ = 61317889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61317923) 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 in 31 ways as a sum of consecutive naturals, for example, 90235 + ... + 90911.

It is an arithmetic number, because the mean of its divisors is an integer number (3091680).

Almost surely, 2^61317921 is an apocalyptic number.

It is an amenable number.

61317921 is a deficient number, since it is larger than the sum of its proper divisors (37615839).

61317921 is a wasteful number, since it uses less digits than its factorization.

61317921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933.

The product of its digits is 2268, while the sum is 30.

The square root of 61317921 is about 7830.5760324513. The cubic root of 61317921 is about 394.3324107722.

The spelling of 61317921 in words is "sixty-one million, three hundred seventeen thousand, nine hundred twenty-one".