261715478 has 4 divisors (see below), whose sum is σ = 392573220. Its totient is φ = 130857738.

The previous prime is 261715477. The next prime is 261715507. The reversal of 261715478 is 874517162.

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 (261715471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65428868 + ... + 65428871.

It is an arithmetic number, because the mean of its divisors is an integer number (98143305).

Almost surely, 2^261715478 is an apocalyptic number.

261715478 is a deficient number, since it is larger than the sum of its proper divisors (130857742).

261715478 is a wasteful number, since it uses less digits than its factorization.

261715478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130857741.

The product of its digits is 94080, while the sum is 41.

The square root of 261715478 is about 16177.6227549044. The cubic root of 261715478 is about 639.6510777089.

The spelling of 261715478 in words is "two hundred sixty-one million, seven hundred fifteen thousand, four hundred seventy-eight".