261511142 has 4 divisors (see below), whose sum is σ = 392266716. Its totient is φ = 130755570.

The previous prime is 261511139. The next prime is 261511147. The reversal of 261511142 is 241115162.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261511147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65377784 + ... + 65377787.

It is an arithmetic number, because the mean of its divisors is an integer number (98066679).

Almost surely, 2^261511142 is an apocalyptic number.

261511142 is a deficient number, since it is larger than the sum of its proper divisors (130755574).

261511142 is a wasteful number, since it uses less digits than its factorization.

261511142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130755573.

The product of its digits is 480, while the sum is 23.

The square root of 261511142 is about 16171.3061315405. The cubic root of 261511142 is about 639.4845638363.

The spelling of 261511142 in words is "two hundred sixty-one million, five hundred eleven thousand, one hundred forty-two".