261421757 has 8 divisors (see below), whose sum is σ = 262846080. Its totient is φ = 260002080.

The previous prime is 261421711. The next prime is 261421763. The reversal of 261421757 is 757124162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261421757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261421157) 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 7 ways as a sum of consecutive naturals, for example, 175538 + ... + 177020.

It is an arithmetic number, because the mean of its divisors is an integer number (32855760).

Almost surely, 2^261421757 is an apocalyptic number.

It is an amenable number.

261421757 is a deficient number, since it is larger than the sum of its proper divisors (1424323).

261421757 is a wasteful number, since it uses less digits than its factorization.

261421757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2323.

The product of its digits is 23520, while the sum is 35.

The square root of 261421757 is about 16168.5422039218. The cubic root of 261421757 is about 639.4116965248.

The spelling of 261421757 in words is "two hundred sixty-one million, four hundred twenty-one thousand, seven hundred fifty-seven".