20926405 has 8 divisors (see below), whose sum is σ = 26588952. Its totient is φ = 15756288.

The previous prime is 20926397. The next prime is 20926427. The reversal of 20926405 is 50462902.

It can be written as a sum of positive squares in 4 ways, for example, as 5692996 + 15233409 = 2386^2 + 3903^2 .

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 20926405 - 2³ = 20926397 is a prime.

It is a congruent number.

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, 123012 + ... + 123181.

It is an arithmetic number, because the mean of its divisors is an integer number (3323619).

Almost surely, 2^20926405 is an apocalyptic number.

It is an amenable number.

20926405 is a deficient number, since it is larger than the sum of its proper divisors (5662547).

20926405 is a wasteful number, since it uses less digits than its factorization.

20926405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246215.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 20926405 is about 4574.5387745651. The cubic root of 20926405 is about 275.5697498963.

The spelling of 20926405 in words is "twenty million, nine hundred twenty-six thousand, four hundred five".