61228907520 has 352 divisors, whose sum is σ = 224896193280. Its totient is φ = 14061404160.

The previous prime is 61228907513. The next prime is 61228907521. The reversal of 61228907520 is 2570982216.

It is a tau number, because it is divible by the number of its divisors (352).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61228907521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3200704 + ... + 3219776.

It is an arithmetic number, because the mean of its divisors is an integer number (638909640).

Almost surely, 2^61228907520 is an apocalyptic number.

61228907520 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 61228907520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112448096640).

61228907520 is an abundant number, since it is smaller than the sum of its proper divisors (163667285760).

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

61228907520 is a wasteful number, since it uses less digits than its factorization.

61228907520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19131 (or 19113 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The spelling of 61228907520 in words is "sixty-one billion, two hundred twenty-eight million, nine hundred seven thousand, five hundred twenty".