261993156 has 24 divisors (see below), whose sum is σ = 614699904. Its totient is φ = 86847840.

The previous prime is 261993101. The next prime is 261993167. The reversal of 261993156 is 651399162.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58140 + ... + 62483.

It is an arithmetic number, because the mean of its divisors is an integer number (25612496).

Almost surely, 2^261993156 is an apocalyptic number.

It is an amenable number.

261993156 is an abundant number, since it is smaller than the sum of its proper divisors (352706748).

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

261993156 is a wasteful number, since it uses less digits than its factorization.

261993156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120811 (or 120809 counting only the distinct ones).

The product of its digits is 87480, while the sum is 42.

The square root of 261993156 is about 16186.2026429920. The cubic root of 261993156 is about 639.8772192852.

The spelling of 261993156 in words is "two hundred sixty-one million, nine hundred ninety-three thousand, one hundred fifty-six".