61621560 has 640 divisors, whose sum is σ = 292723200. Its totient is φ = 11197440.

The previous prime is 61621517. The next prime is 61621589. The reversal of 61621560 is 6512616.

It is a happy number.

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 159 ways as a sum of consecutive naturals, for example, 3243231 + ... + 3243249.

It is an arithmetic number, because the mean of its divisors is an integer number (457380).

Almost surely, 2^61621560 is an apocalyptic number.

61621560 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 61621560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146361600).

61621560 is an abundant number, since it is smaller than the sum of its proper divisors (231101640).

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

61621560 is a wasteful number, since it uses less digits than its factorization.

61621560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 61621560 is about 7849.9401271602. The cubic root of 61621560 is about 394.9822349538.

The spelling of 61621560 in words is "sixty-one million, six hundred twenty-one thousand, five hundred sixty".