261543402 has 48 divisors (see below), whose sum is σ = 620722440. Its totient is φ = 79220736.

The previous prime is 261543397. The next prime is 261543413. The reversal of 261543402 is 204345162.

261543402 is a `hidden beast` number, since 2 + 615 + 4 + 3 + 40 + 2 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 227074761 + 34468641 = 15069^2 + 5871^2 .

It is a super-2 number, since 2×261543402² = 136809902259467208, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5863 + ... + 23610.

Almost surely, 2^261543402 is an apocalyptic number.

261543402 is an abundant number, since it is smaller than the sum of its proper divisors (359179038).

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

261543402 is a wasteful number, since it uses less digits than its factorization.

261543402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29527 (or 29524 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 261543402 is about 16172.3035464958. The cubic root of 261543402 is about 639.5108583485.

Adding to 261543402 its reverse (204345162), we get a palindrome (465888564).

The spelling of 261543402 in words is "two hundred sixty-one million, five hundred forty-three thousand, four hundred two".