261671630 has 32 divisors (see below), whose sum is σ = 514805760. Its totient is φ = 94972320.

The previous prime is 261671617. The next prime is 261671647. The reversal of 261671630 is 36176162.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64811 + ... + 68729.

It is an arithmetic number, because the mean of its divisors is an integer number (16087680).

Almost surely, 2^261671630 is an apocalyptic number.

261671630 is a deficient number, since it is larger than the sum of its proper divisors (253134130).

261671630 is a wasteful number, since it uses less digits than its factorization.

261671630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4544.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 261671630 is about 16176.2674928427. The cubic root of 261671630 is about 639.6153531794.

The spelling of 261671630 in words is "two hundred sixty-one million, six hundred seventy-one thousand, six hundred thirty".