261572461 has 2 divisors, whose sum is σ = 261572462. Its totient is φ = 261572460.

The previous prime is 261572447. The next prime is 261572477. The reversal of 261572461 is 164275162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153016900 + 108555561 = 12370^2 + 10419^2 .

It is a cyclic number.

It is not a de Polignac number, because 261572461 - 2⁹ = 261571949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261572401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130786230 + 130786231.

It is an arithmetic number, because the mean of its divisors is an integer number (130786231).

Almost surely, 2^261572461 is an apocalyptic number.

It is an amenable number.

261572461 is a deficient number, since it is larger than the sum of its proper divisors (1).

261572461 is an equidigital number, since it uses as much as digits as its factorization.

261572461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 34.

The square root of 261572461 is about 16173.2019402467. The cubic root of 261572461 is about 639.5345419356.

It can be divided in two parts, 2615 and 72461, that added together give a square (75076 = 274²).

The spelling of 261572461 in words is "two hundred sixty-one million, five hundred seventy-two thousand, four hundred sixty-one".