261352557 has 6 divisors (see below), whose sum is σ = 377509262. Its totient is φ = 174235032.

The previous prime is 261352499. The next prime is 261352589. The reversal of 261352557 is 755253162.

It can be written as a sum of positive squares in only one way, i.e., 155900196 + 105452361 = 12486^2 + 10269^2 .

It is a de Polignac number, because none of the positive numbers 2^k-261352557 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 (261352757) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14519578 + ... + 14519595.

Almost surely, 2^261352557 is an apocalyptic number.

It is an amenable number.

261352557 is a deficient number, since it is larger than the sum of its proper divisors (116156705).

261352557 is a wasteful number, since it uses less digits than its factorization.

261352557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29039179 (or 29039176 counting only the distinct ones).

The product of its digits is 63000, while the sum is 36.

The square root of 261352557 is about 16166.4021043645. The cubic root of 261352557 is about 639.3552727665.

The spelling of 261352557 in words is "two hundred sixty-one million, three hundred fifty-two thousand, five hundred fifty-seven".