61731216 has 120 divisors (see below), whose sum is σ = 185238144. Its totient is φ = 19123200.

The previous prime is 61731211. The next prime is 61731217. The reversal of 61731216 is 61213716.

61731216 is a `hidden beast` number, since 617 + 31 + 2 + 16 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 61731216.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61731211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 369565 + ... + 369731.

Almost surely, 2^61731216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61731216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92619072).

61731216 is an abundant number, since it is smaller than the sum of its proper divisors (123506928).

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

61731216 is a wasteful number, since it uses less digits than its factorization.

61731216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349 (or 340 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 61731216 is about 7856.9215345452. The cubic root of 61731216 is about 395.2163873397.

The spelling of 61731216 in words is "sixty-one million, seven hundred thirty-one thousand, two hundred sixteen".