20969857 has 8 divisors (see below), whose sum is σ = 22920192. Its totient is φ = 19099200.

The previous prime is 20969833. The next prime is 20969869. The reversal of 20969857 is 75896902.

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-20969857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20969827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19369 + ... + 20422.

It is an arithmetic number, because the mean of its divisors is an integer number (2865024).

Almost surely, 2^20969857 is an apocalyptic number.

It is an amenable number.

20969857 is a deficient number, since it is larger than the sum of its proper divisors (1950335).

20969857 is a wasteful number, since it uses less digits than its factorization.

20969857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39839.

The product of its (nonzero) digits is 272160, while the sum is 46.

The square root of 20969857 is about 4579.2856429797. The cubic root of 20969857 is about 275.7603508555.

The spelling of 20969857 in words is "twenty million, nine hundred sixty-nine thousand, eight hundred fifty-seven".