261621926 has 12 divisors (see below), whose sum is σ = 397898532. Its totient is φ = 129013776.

The previous prime is 261621889. The next prime is 261621929. The reversal of 261621926 is 629126162.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261621929) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1616 + ... + 22931.

It is an arithmetic number, because the mean of its divisors is an integer number (33158211).

Almost surely, 2^261621926 is an apocalyptic number.

261621926 is a deficient number, since it is larger than the sum of its proper divisors (136276606).

261621926 is an equidigital number, since it uses as much as digits as its factorization.

261621926 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24695 (or 24622 counting only the distinct ones).

The product of its digits is 15552, while the sum is 35.

The square root of 261621926 is about 16174.7310951373. The cubic root of 261621926 is about 639.5748527315.

It can be divided in two parts, 2616 and 21926, that added together give a palindrome (24542).

The spelling of 261621926 in words is "two hundred sixty-one million, six hundred twenty-one thousand, nine hundred twenty-six".