261687298 has 4 divisors (see below), whose sum is σ = 392530950. Its totient is φ = 130843648.

The previous prime is 261687281. The next prime is 261687317. The reversal of 261687298 is 892786162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 892786162 = 2 ⋅446393081.

It can be written as a sum of positive squares in only one way, i.e., 245016409 + 16670889 = 15653^2 + 4083^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65421823 + ... + 65421826.

Almost surely, 2^261687298 is an apocalyptic number.

261687298 is a deficient number, since it is larger than the sum of its proper divisors (130843652).

261687298 is a wasteful number, since it uses less digits than its factorization.

261687298 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130843651.

The product of its digits is 580608, while the sum is 49.

The square root of 261687298 is about 16176.7517753101. The cubic root of 261687298 is about 639.6281189160.

The spelling of 261687298 in words is "two hundred sixty-one million, six hundred eighty-seven thousand, two hundred ninety-eight".