61531272 has 256 divisors, whose sum is σ = 207360000. Its totient is φ = 16692480.

The previous prime is 61531247. The next prime is 61531289. The reversal of 61531272 is 27213516.

It is a happy number.

61531272 is a `hidden beast` number, since 61 + 531 + 2 + 72 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1309153 + ... + 1309199.

It is an arithmetic number, because the mean of its divisors is an integer number (810000).

Almost surely, 2^61531272 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 61531272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103680000).

61531272 is an abundant number, since it is smaller than the sum of its proper divisors (145828728).

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

61531272 is a wasteful number, since it uses less digits than its factorization.

61531272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121 (or 111 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 61531272 is about 7844.1871471810. The cubic root of 61531272 is about 394.7892311435.

Adding to 61531272 its reverse (27213516), we get a palindrome (88744788).

The spelling of 61531272 in words is "sixty-one million, five hundred thirty-one thousand, two hundred seventy-two".