61509972 has 24 divisors (see below), whose sum is σ = 145254816. Its totient is φ = 20255968.

The previous prime is 61509967. The next prime is 61509991. The reversal of 61509972 is 27990516.

It is a self number, because there is not a number n which added to its sum of digits gives 61509972.

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, 29883 + ... + 31874.

It is an arithmetic number, because the mean of its divisors is an integer number (6052284).

Almost surely, 2^61509972 is an apocalyptic number.

It is an amenable number.

61509972 is an abundant number, since it is smaller than the sum of its proper divisors (83744844).

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

61509972 is a wasteful number, since it uses less digits than its factorization.

61509972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61847 (or 61845 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 39.

The square root of 61509972 is about 7842.8293364066. The cubic root of 61509972 is about 394.7436717565.

It can be divided in two parts, 61509 and 972, that added together give a triangular number (62481 = T₃₅₃).

The spelling of 61509972 in words is "sixty-one million, five hundred nine thousand, nine hundred seventy-two".