261335042 has 4 divisors (see below), whose sum is σ = 392002566. Its totient is φ = 130667520.

The previous prime is 261335027. The next prime is 261335047. The reversal of 261335042 is 240533162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 240533162 = 2 ⋅120266581.

It can be written as a sum of positive squares in only one way, i.e., 242767561 + 18567481 = 15581^2 + 4309^2 .

It is not an unprimeable number, because it can be changed into a prime (261335047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65333759 + ... + 65333762.

Almost surely, 2^261335042 is an apocalyptic number.

261335042 is a deficient number, since it is larger than the sum of its proper divisors (130667524).

261335042 is a wasteful number, since it uses less digits than its factorization.

261335042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130667523.

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 261335042 is about 16165.8603853924. The cubic root of 261335042 is about 639.3409899424.

The spelling of 261335042 in words is "two hundred sixty-one million, three hundred thirty-five thousand, forty-two".