61859831520 has 48 divisors (see below), whose sum is σ = 194858470800. Its totient is φ = 16495954944.

The previous prime is 61859831507. The next prime is 61859831521. The reversal of 61859831520 is 2513895816.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 61859831520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61859831521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64436845 + ... + 64437804.

It is an arithmetic number, because the mean of its divisors is an integer number (4059551475).

Almost surely, 2^61859831520 is an apocalyptic number.

61859831520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61859831520 is an abundant number, since it is smaller than the sum of its proper divisors (132998639280).

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

61859831520 is a wasteful number, since it uses less digits than its factorization.

61859831520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128874667 (or 128874659 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 48.

The spelling of 61859831520 in words is "sixty-one billion, eight hundred fifty-nine million, eight hundred thirty-one thousand, five hundred twenty".