61638201 has 9 divisors (see below), whose sum is σ = 89066991. Its totient is φ = 41076432.

The previous prime is 61638167. The next prime is 61638233. The reversal of 61638201 is 10283616.

The square root of 61638201 is 7851.

It is a perfect power (a square), and thus also a powerful number.

61638201 is a `hidden beast` number, since 6 + 1 + 638 + 20 + 1 = 666.

61638201 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 60140025 + 1498176 = 7755^2 + 1224^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 61638201 - 2⁹ = 61637689 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61638281) 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 8 ways as a sum of consecutive naturals, for example, 22245 + ... + 24861.

Almost surely, 2^61638201 is an apocalyptic number.

61638201 is the 7851-st square number.

61638201 is the 3926-th centered octagonal number.

It is an amenable number.

61638201 is a deficient number, since it is larger than the sum of its proper divisors (27428790).

61638201 is an frugal number, since it uses more digits than its factorization.

61638201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5240 (or 2620 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The cubic root of 61638201 is about 395.0177869467.

The spelling of 61638201 in words is "sixty-one million, six hundred thirty-eight thousand, two hundred one".