661251412260 has 144 divisors (see below), whose sum is σ = 2052906920064. Its totient is φ = 172193946624.

The previous prime is 661251412259. The next prime is 661251412277. The reversal of 661251412260 is 62214152166.

661251412260 is a `hidden beast` number, since 6 + 6 + 12 + 514 + 122 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 52881169 + ... + 52893671.

It is an arithmetic number, because the mean of its divisors is an integer number (14256298056).

Almost surely, 2^661251412260 is an apocalyptic number.

661251412260 is a gapful number since it is divisible by the number (60) 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 661251412260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1026453460032).

661251412260 is an abundant number, since it is smaller than the sum of its proper divisors (1391655507804).

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

661251412260 is a wasteful number, since it uses less digits than its factorization.

661251412260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19394 (or 19389 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 661251412260 in words is "six hundred sixty-one billion, two hundred fifty-one million, four hundred twelve thousand, two hundred sixty".