261449631 has 12 divisors (see below), whose sum is σ = 382430880. Its totient is φ = 172092960.

The previous prime is 261449627. The next prime is 261449641. The reversal of 261449631 is 136944162.

261449631 is a `hidden beast` number, since 2 + 6 + 14 + 4 + 9 + 631 = 666.

It is not a de Polignac number, because 261449631 - 2² = 261449627 is a prime.

It is a super-2 number, since 2×261449631² = 136711819100072322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261449621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 183150 + ... + 184571.

It is an arithmetic number, because the mean of its divisors is an integer number (31869240).

Almost surely, 2^261449631 is an apocalyptic number.

261449631 is a deficient number, since it is larger than the sum of its proper divisors (120981249).

261449631 is a wasteful number, since it uses less digits than its factorization.

261449631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367806 (or 367803 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 261449631 is about 16169.4041634193. The cubic root of 261449631 is about 639.4344213972.

The spelling of 261449631 in words is "two hundred sixty-one million, four hundred forty-nine thousand, six hundred thirty-one".