61639225 has 18 divisors (see below), whose sum is σ = 78597834. Its totient is φ = 47952000.

The previous prime is 61639213. The next prime is 61639271. The reversal of 61639225 is 52293616.

61639225 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 9 ways, for example, as 4968441 + 56670784 = 2229^2 + 7528^2 .

It is not a de Polignac number, because 61639225 - 2⁹ = 61638713 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 33325 + ... + 35125.

Almost surely, 2^61639225 is an apocalyptic number.

It is an amenable number.

61639225 is a deficient number, since it is larger than the sum of its proper divisors (16958609).

61639225 is a wasteful number, since it uses less digits than its factorization.

61639225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1885 (or 1843 counting only the distinct ones).

The product of its digits is 19440, while the sum is 34.

The square root of 61639225 is about 7851.0652143515. The cubic root of 61639225 is about 395.0199744212.

The spelling of 61639225 in words is "sixty-one million, six hundred thirty-nine thousand, two hundred twenty-five".