261291996 has 36 divisors (see below), whose sum is σ = 754844272. Its totient is φ = 74654784.

The previous prime is 261291929. The next prime is 261291997. The reversal of 261291996 is 699192162.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261291997) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 518185 + ... + 518688.

Almost surely, 2^261291996 is an apocalyptic number.

It is an amenable number.

261291996 is an abundant number, since it is smaller than the sum of its proper divisors (493552276).

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

261291996 is a wasteful number, since it uses less digits than its factorization.

261291996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1036890 (or 1036885 counting only the distinct ones).

The product of its digits is 104976, while the sum is 45.

The square root of 261291996 is about 16164.5289445749. The cubic root of 261291996 is about 639.3058848359.

The spelling of 261291996 in words is "two hundred sixty-one million, two hundred ninety-one thousand, nine hundred ninety-six".