261954500378220 has 72 divisors (see below), whose sum is σ = 855718034576496. Its totient is φ = 64481107784832.

The previous prime is 261954500378203. The next prime is 261954500378257. The reversal of 261954500378220 is 22873005459162.

261954500378220 is a `hidden beast` number, since 2 + 6 + 1 + 9 + 5 + 4 + 500 + 37 + 82 + 20 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 55973181502 + ... + 55973186181.

It is a 1-persistent number, because it is pandigital, but 2⋅261954500378220 = 523909000756440 is not.

Almost surely, 2^{261954500378220} is an apocalyptic number.

261954500378220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261954500378220 is an abundant number, since it is smaller than the sum of its proper divisors (593763534198276).

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

261954500378220 is a wasteful number, since it uses less digits than its factorization.

261954500378220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111946367711 (or 111946367706 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 54.

The spelling of 261954500378220 in words is "two hundred sixty-one trillion, nine hundred fifty-four billion, five hundred million, three hundred seventy-eight thousand, two hundred twenty".