261666447353100 has 54 divisors (see below), whose sum is σ = 820178942206260. Its totient is φ = 69777719293920.

The previous prime is 261666447353089. The next prime is 261666447353111. The reversal of 261666447353100 is 1353744666162.

It is an interprime number because it is at equal distance from previous prime (261666447353089) and next prime (261666447353111).

It is a super-2 number, since 2×261666447353100² (a number of 30 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 145370247630 + ... + 145370249429.

Almost surely, 2^{261666447353100} is an apocalyptic number.

261666447353100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261666447353100 is an abundant number, since it is smaller than the sum of its proper divisors (558512494853160).

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

261666447353100 is a wasteful number, since it uses less digits than its factorization.

261666447353100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290740497079 (or 290740497069 counting only the distinct ones).

The product of its (nonzero) digits is 13063680, while the sum is 54.

The spelling of 261666447353100 in words is "two hundred sixty-one trillion, six hundred sixty-six billion, four hundred forty-seven million, three hundred fifty-three thousand, one hundred".