261421167574620 has 144 divisors (see below), whose sum is σ = 795020414916000. Its totient is φ = 69532877703168.

The previous prime is 261421167574613. The next prime is 261421167574663. The reversal of 261421167574620 is 26475761124162.

261421167574620 is a `hidden beast` number, since 2 + 6 + 1 + 4 + 2 + 1 + 1 + 6 + 7 + 5 + 7 + 4 + 620 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 156624312 + ... + 158284608.

Almost surely, 2^{261421167574620} is an apocalyptic number.

261421167574620 is a gapful number since it is divisible by the number (20) 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 261421167574620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (397510207458000).

261421167574620 is an abundant number, since it is smaller than the sum of its proper divisors (533599247341380).

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

261421167574620 is a wasteful number, since it uses less digits than its factorization.

261421167574620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1662564 (or 1662559 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 54.

The spelling of 261421167574620 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, one hundred sixty-seven million, five hundred seventy-four thousand, six hundred twenty".