61555725 has 216 divisors, whose sum is σ = 154365120. Its totient is φ = 22809600.

The previous prime is 61555667. The next prime is 61555729. The reversal of 61555725 is 52755516.

It is a happy number.

It is not a de Polignac number, because 61555725 - 2⁷ = 61555597 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61555725.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61555729) by changing a digit.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 3239766 + ... + 3239784.

Almost surely, 2^61555725 is an apocalyptic number.

It is an amenable number.

61555725 is an abundant number, since it is smaller than the sum of its proper divisors (92809395).

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

61555725 is a wasteful number, since it uses less digits than its factorization.

61555725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 62 counting only the distinct ones).

The product of its digits is 52500, while the sum is 36.

The square root of 61555725 is about 7845.7456624594. The cubic root of 61555725 is about 394.8415216413.

The spelling of 61555725 in words is "sixty-one million, five hundred fifty-five thousand, seven hundred twenty-five".