20261905 has 8 divisors (see below), whose sum is σ = 24451200. Its totient is φ = 16118256.

The previous prime is 20261897. The next prime is 20261911. The reversal of 20261905 is 50916202.

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

It is a cyclic number.

It is not a de Polignac number, because 20261905 - 2³ = 20261897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20261905.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10425 + ... + 12214.

It is an arithmetic number, because the mean of its divisors is an integer number (3056400).

Almost surely, 2^20261905 is an apocalyptic number.

It is an amenable number.

20261905 is a deficient number, since it is larger than the sum of its proper divisors (4189295).

20261905 is a wasteful number, since it uses less digits than its factorization.

20261905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22823.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 20261905 is about 4501.3225834192. The cubic root of 20261905 is about 272.6214928328.

The spelling of 20261905 in words is "twenty million, two hundred sixty-one thousand, nine hundred five".