61644590 has 32 divisors (see below), whose sum is σ = 130244544. Its totient is φ = 20563200.

The previous prime is 61644581. The next prime is 61644613. The reversal of 61644590 is 9544616.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 61644590.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9311 + ... + 14490.

It is an arithmetic number, because the mean of its divisors is an integer number (4070142).

Almost surely, 2^61644590 is an apocalyptic number.

61644590 is an abundant number, since it is smaller than the sum of its proper divisors (68599954).

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

61644590 is a wasteful number, since it uses less digits than its factorization.

61644590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23852.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 61644590 is about 7851.4068802986. The cubic root of 61644590 is about 395.0314347680.

The spelling of 61644590 in words is "sixty-one million, six hundred forty-four thousand, five hundred ninety".