61309072 has 80 divisors (see below), whose sum is σ = 141848064. Its totient is φ = 25344000.

The previous prime is 61309069. The next prime is 61309081. The reversal of 61309072 is 27090316.

It is a self number, because there is not a number n which added to its sum of digits gives 61309072.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92422 + ... + 93082.

Almost surely, 2^61309072 is an apocalyptic number.

61309072 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61309072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70924032).

61309072 is an abundant number, since it is smaller than the sum of its proper divisors (80538992).

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

61309072 is a wasteful number, since it uses less digits than its factorization.

61309072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728 (or 722 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 61309072 is about 7830.0109833895. The cubic root of 61309072 is about 394.3134407043.

Adding to 61309072 its reverse (27090316), we get a palindrome (88399388).

The spelling of 61309072 in words is "sixty-one million, three hundred nine thousand, seventy-two".