61731072 has 180 divisors, whose sum is σ = 199095820. Its totient is φ = 18911232.

The previous prime is 61731067. The next prime is 61731077. The reversal of 61731072 is 27013716.

It is an interprime number because it is at equal distance from previous prime (61731067) and next prime (61731077).

It can be written as a sum of positive squares in 2 ways, for example, as 34857216 + 26873856 = 5904^2 + 5184^2 .

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

It is not an unprimeable number, because it can be changed into a prime (61731077) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 269454 + ... + 269682.

Almost surely, 2^61731072 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 61731072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99547910).

61731072 is an abundant number, since it is smaller than the sum of its proper divisors (137364748).

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

61731072 is a wasteful number, since it uses less digits than its factorization.

61731072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 61731072 is about 7856.9123706454. The cubic root of 61731072 is about 395.2160800333.

Adding to 61731072 its reverse (27013716), we get a palindrome (88744788).

The spelling of 61731072 in words is "sixty-one million, seven hundred thirty-one thousand, seventy-two".