61513991424 has 216 divisors, whose sum is σ = 192721401600. Its totient is φ = 18798428160.

The previous prime is 61513991387. The next prime is 61513991449. The reversal of 61513991424 is 42419931516.

61513991424 is a `hidden beast` number, since 6 + 1 + 5 + 139 + 91 + 424 = 666.

It is a super-2 number, since 2×61513991424² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 61513991424.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1334392 + ... + 1379720.

Almost surely, 2^61513991424 is an apocalyptic number.

61513991424 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 61513991424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96360700800).

61513991424 is an abundant number, since it is smaller than the sum of its proper divisors (131207410176).

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

61513991424 is a wasteful number, since it uses less digits than its factorization.

61513991424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45401 (or 45384 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The spelling of 61513991424 in words is "sixty-one billion, five hundred thirteen million, nine hundred ninety-one thousand, four hundred twenty-four".