261978524 has 12 divisors (see below), whose sum is σ = 461809824. Its totient is φ = 130032864.

The previous prime is 261978499. The next prime is 261978527. The reversal of 261978524 is 425879162.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261978527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 238484 + ... + 239579.

It is an arithmetic number, because the mean of its divisors is an integer number (38484152).

Almost surely, 2^261978524 is an apocalyptic number.

It is an amenable number.

261978524 is a deficient number, since it is larger than the sum of its proper divisors (199831300).

261978524 is a wasteful number, since it uses less digits than its factorization.

261978524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478204 (or 478202 counting only the distinct ones).

The product of its digits is 241920, while the sum is 44.

The square root of 261978524 is about 16185.7506467881. The cubic root of 261978524 is about 639.8653069412.

The spelling of 261978524 in words is "two hundred sixty-one million, nine hundred seventy-eight thousand, five hundred twenty-four".