61931645 has 12 divisors (see below), whose sum is σ = 76798620. Its totient is φ = 47943360.

The previous prime is 61931641. The next prime is 61931647. The reversal of 61931645 is 54613916.

It can be written as a sum of positive squares in 2 ways, for example, as 31483321 + 30448324 = 5611^2 + 5518^2 .

It is not a de Polignac number, because 61931645 - 2² = 61931641 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61931641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1640 + ... + 11249.

It is an arithmetic number, because the mean of its divisors is an integer number (6399885).

Almost surely, 2^61931645 is an apocalyptic number.

It is an amenable number.

61931645 is a deficient number, since it is larger than the sum of its proper divisors (14866975).

61931645 is a wasteful number, since it uses less digits than its factorization.

61931645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12956 (or 12925 counting only the distinct ones).

The product of its digits is 19440, while the sum is 35.

The square root of 61931645 is about 7869.6661301481. Note that the first 3 decimals coincide. The cubic root of 61931645 is about 395.6436549648.

The spelling of 61931645 in words is "sixty-one million, nine hundred thirty-one thousand, six hundred forty-five".