61408804864 has 115 divisors (see below), whose sum is σ = 135098515735. Its totient is φ = 27913093120.

The previous prime is 61408804823. The next prime is 61408804939. The reversal of 61408804864 is 46840880416.

It is a happy number.

The square root of 61408804864 is 247808.

It is a perfect power (a square), and thus also a powerful number.

It is an ABA number since it can be written as A⋅B^A, here for A=4, B=352.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 4 ways as a sum of consecutive naturals, for example, 5582618619 + ... + 5582618629.

Almost surely, 2^61408804864 is an apocalyptic number.

61408804864 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

61408804864 is a droll number since its even prime factors and its odd prime factors have the same sum.

61408804864 is the 247808-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61408804864

61408804864 is an abundant number, since it is smaller than the sum of its proper divisors (73689710871).

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

61408804864 is an frugal number, since it uses more digits than its factorization.

61408804864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88 (or 13 counting only the distinct ones).

The product of its (nonzero) digits is 1179648, while the sum is 49.

Multiplying 61408804864 by its sum of digits (49), we get a square (3009031438336 = 1734656²).

The spelling of 61408804864 in words is "sixty-one billion, four hundred eight million, eight hundred four thousand, eight hundred sixty-four".