261072405 has 24 divisors (see below), whose sum is σ = 493665120. Its totient is φ = 126580320.

The previous prime is 261072391. The next prime is 261072419. The reversal of 261072405 is 504270162.

261072405 is a `hidden beast` number, since 2 + 610 + 7 + 2 + 40 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (261072391) and next prime (261072419).

It is not a de Polignac number, because 261072405 - 2¹³ = 261064213 is a prime.

It is a congruent number.

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, 263215 + ... + 264204.

It is an arithmetic number, because the mean of its divisors is an integer number (20569380).

Almost surely, 2^261072405 is an apocalyptic number.

It is an amenable number.

261072405 is a deficient number, since it is larger than the sum of its proper divisors (232592715).

261072405 is a wasteful number, since it uses less digits than its factorization.

261072405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527441 (or 527438 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 261072405 is about 16157.7351445059. The cubic root of 261072405 is about 639.1267427700.

The spelling of 261072405 in words is "two hundred sixty-one million, seventy-two thousand, four hundred five".