261521142 has 8 divisors (see below), whose sum is σ = 523042296. Its totient is φ = 87173712.

The previous prime is 261521137. The next prime is 261521147. The reversal of 261521142 is 241125162.

It is an interprime number because it is at equal distance from previous prime (261521137) and next prime (261521147).

It is a sphenic number, since it is the product of 3 distinct primes.

261521142 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261521147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21793423 + ... + 21793434.

It is an arithmetic number, because the mean of its divisors is an integer number (65380287).

Almost surely, 2^261521142 is an apocalyptic number.

261521142 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

261521142 is a wasteful number, since it uses less digits than its factorization.

261521142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43586862.

The product of its digits is 960, while the sum is 24.

The square root of 261521142 is about 16171.6153182049. The cubic root of 261521142 is about 639.4927148773.

The spelling of 261521142 in words is "two hundred sixty-one million, five hundred twenty-one thousand, one hundred forty-two".