261564670 has 16 divisors (see below), whose sum is σ = 486004608. Its totient is φ = 101250720.

The previous prime is 261564643. The next prime is 261564683. The reversal of 261564670 is 76465162.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 421569 + ... + 422188.

It is an arithmetic number, because the mean of its divisors is an integer number (30375288).

Almost surely, 2^261564670 is an apocalyptic number.

261564670 is a deficient number, since it is larger than the sum of its proper divisors (224439938).

261564670 is a wasteful number, since it uses less digits than its factorization.

261564670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843795.

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 261564670 is about 16172.9610770570. The cubic root of 261564670 is about 639.5281923081.

The spelling of 261564670 in words is "two hundred sixty-one million, five hundred sixty-four thousand, six hundred seventy".