61530521344 has 72 divisors (see below), whose sum is σ = 131197328640. Its totient is φ = 28699066368.

The previous prime is 61530521309. The next prime is 61530521369. The reversal of 61530521344 is 44312503516.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 429217 + ... + 554335.

It is an arithmetic number, because the mean of its divisors is an integer number (1822185120).

Almost surely, 2^61530521344 is an apocalyptic number.

61530521344 is a gapful number since it is divisible by the number (64) 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 61530521344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65598664320).

61530521344 is an abundant number, since it is smaller than the sum of its proper divisors (69666807296).

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

61530521344 is a wasteful number, since it uses less digits than its factorization.

61530521344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125265 (or 125251 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 34.

The spelling of 61530521344 in words is "sixty-one billion, five hundred thirty million, five hundred twenty-one thousand, three hundred forty-four".