61878308864 has 104 divisors (see below), whose sum is σ = 127067965920. Its totient is φ = 30117920768.

The previous prime is 61878308837. The next prime is 61878308903. The reversal of 61878308864 is 46880387816.

It is a Harshad number since it is a multiple of its sum of digits (59).

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 7 ways as a sum of consecutive naturals, for example, 25856852 + ... + 25859244.

Almost surely, 2^61878308864 is an apocalyptic number.

61878308864 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 61878308864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63533982960).

61878308864 is an abundant number, since it is smaller than the sum of its proper divisors (65189657056).

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

61878308864 is a wasteful number, since it uses less digits than its factorization.

61878308864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2583 (or 2561 counting only the distinct ones).

The product of its (nonzero) digits is 12386304, while the sum is 59.

The spelling of 61878308864 in words is "sixty-one billion, eight hundred seventy-eight million, three hundred eight thousand, eight hundred sixty-four".