61638544 has 20 divisors (see below), whose sum is σ = 130281840. Its totient is φ = 28017440.

The previous prime is 61638529. The next prime is 61638547. The reversal of 61638544 is 44583616.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (61638547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 174934 + ... + 175285.

It is an arithmetic number, because the mean of its divisors is an integer number (6514092).

Almost surely, 2^61638544 is an apocalyptic number.

It is an amenable number.

61638544 is an abundant number, since it is smaller than the sum of its proper divisors (68643296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61638544 is a wasteful number, since it uses less digits than its factorization.

61638544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350238 (or 350232 counting only the distinct ones).

The product of its digits is 69120, while the sum is 37.

The square root of 61638544 is about 7851.0218443206. The cubic root of 61638544 is about 395.0185196679.

The spelling of 61638544 in words is "sixty-one million, six hundred thirty-eight thousand, five hundred forty-four".