261157786 has 4 divisors (see below), whose sum is σ = 391736682. Its totient is φ = 130578892.

The previous prime is 261157763. The next prime is 261157811. The reversal of 261157786 is 687751162.

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

It can be written as a sum of positive squares in only one way, i.e., 192682161 + 68475625 = 13881^2 + 8275^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65289445 + ... + 65289448.

Almost surely, 2^261157786 is an apocalyptic number.

261157786 is a deficient number, since it is larger than the sum of its proper divisors (130578896).

261157786 is a wasteful number, since it uses less digits than its factorization.

261157786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130578895.

The product of its digits is 141120, while the sum is 43.

The square root of 261157786 is about 16160.3770376808. The cubic root of 261157786 is about 639.1964084154.

The spelling of 261157786 in words is "two hundred sixty-one million, one hundred fifty-seven thousand, seven hundred eighty-six".