61638205 has 8 divisors (see below), whose sum is σ = 75361752. Its totient is φ = 48379968.

The previous prime is 61638167. The next prime is 61638233. The reversal of 61638205 is 50283616.

It can be written as a sum of positive squares in 4 ways, for example, as 22174681 + 39463524 = 4709^2 + 6282^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61638205 - 2¹⁵ = 61605437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 116034 + ... + 116563.

It is an arithmetic number, because the mean of its divisors is an integer number (9420219).

Almost surely, 2^61638205 is an apocalyptic number.

It is an amenable number.

61638205 is a deficient number, since it is larger than the sum of its proper divisors (13723547).

61638205 is a wasteful number, since it uses less digits than its factorization.

61638205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232655.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 61638205 is about 7851.0002547446. Note that the first 3 decimals coincide. The cubic root of 61638205 is about 395.0177954916.

The spelling of 61638205 in words is "sixty-one million, six hundred thirty-eight thousand, two hundred five".