20907861 has 8 divisors (see below), whose sum is σ = 30021600. Its totient is φ = 12866352.

The previous prime is 20907839. The next prime is 20907863. The reversal of 20907861 is 16870902.

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

It is not a de Polignac number, because 20907861 - 2¹⁵ = 20875093 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20907863) 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, 268011 + ... + 268088.

It is an arithmetic number, because the mean of its divisors is an integer number (3752700).

Almost surely, 2^20907861 is an apocalyptic number.

It is an amenable number.

20907861 is a deficient number, since it is larger than the sum of its proper divisors (9113739).

20907861 is a wasteful number, since it uses less digits than its factorization.

20907861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536115.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 20907861 is about 4572.5114543323. The cubic root of 20907861 is about 275.4883268385.

The spelling of 20907861 in words is "twenty million, nine hundred seven thousand, eight hundred sixty-one".