20839851 has 6 divisors (see below), whose sum is σ = 30102020. Its totient is φ = 13893228.

The previous prime is 20839829. The next prime is 20839867. The reversal of 20839851 is 15893802.

It is not a de Polignac number, because 20839851 - 2⁹ = 20839339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20839801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1157761 + ... + 1157778.

Almost surely, 2^20839851 is an apocalyptic number.

20839851 is a deficient number, since it is larger than the sum of its proper divisors (9262169).

20839851 is a wasteful number, since it uses less digits than its factorization.

20839851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2315545 (or 2315542 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 20839851 is about 4565.0685646549. The cubic root of 20839851 is about 275.1892955643.

The spelling of 20839851 in words is "twenty million, eight hundred thirty-nine thousand, eight hundred fifty-one".