261999970 has 8 divisors (see below), whose sum is σ = 471599964. Its totient is φ = 104799984.

The previous prime is 261999931. The next prime is 261999977. The reversal of 261999970 is 79999162.

It can be written as a sum of positive squares in 2 ways, for example, as 255904009 + 6095961 = 15997^2 + 2469^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (261999977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13099989 + ... + 13100008.

Almost surely, 2^261999970 is an apocalyptic number.

261999970 is a deficient number, since it is larger than the sum of its proper divisors (209599994).

261999970 is a wasteful number, since it uses less digits than its factorization.

261999970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26200004.

The product of its (nonzero) digits is 551124, while the sum is 52.

The square root of 261999970 is about 16186.4131295355. The cubic root of 261999970 is about 639.8827666128.

The spelling of 261999970 in words is "two hundred sixty-one million, nine hundred ninety-nine thousand, nine hundred seventy".