261631476 has 36 divisors (see below), whose sum is σ = 661840452. Its totient is φ = 87145344.

The previous prime is 261631471. The next prime is 261631493. The reversal of 261631476 is 674136162.

It is a happy number.

261631476 is a `hidden beast` number, since 2 + 616 + 31 + 4 + 7 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 97535376 + 164096100 = 9876^2 + 12810^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 261631476.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261631471) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84630 + ... + 87666.

It is an arithmetic number, because the mean of its divisors is an integer number (18384457).

Almost surely, 2^261631476 is an apocalyptic number.

It is an amenable number.

261631476 is an abundant number, since it is smaller than the sum of its proper divisors (400208976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261631476 is a wasteful number, since it uses less digits than its factorization.

261631476 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5440 (or 5435 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 261631476 is about 16175.0263060064. The cubic root of 261631476 is about 639.5826347825.

The spelling of 261631476 in words is "two hundred sixty-one million, six hundred thirty-one thousand, four hundred seventy-six".