61455720 has 64 divisors (see below), whose sum is σ = 188879040. Its totient is φ = 15987200.

The previous prime is 61455703. The next prime is 61455721. The reversal of 61455720 is 2755416.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (61455721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1326 + ... + 11165.

It is an arithmetic number, because the mean of its divisors is an integer number (2951235).

Almost surely, 2^61455720 is an apocalyptic number.

61455720 is a gapful number since it is divisible by the number (60) 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 61455720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94439520).

61455720 is an abundant number, since it is smaller than the sum of its proper divisors (127423320).

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

61455720 is a wasteful number, since it uses less digits than its factorization.

61455720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12546 (or 12542 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 61455720 is about 7839.3698726364. The cubic root of 61455720 is about 394.6275825420.

The spelling of 61455720 in words is "sixty-one million, four hundred fifty-five thousand, seven hundred twenty".