20894951865 has 16 divisors (see below), whose sum is σ = 33575413248. Its totient is φ = 11096144256.

The previous prime is 20894951839. The next prime is 20894951911. The reversal of 20894951865 is 56815949802.

It is a happy number.

It is not a de Polignac number, because 20894951865 - 2⁶ = 20894951801 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2985769 + ... + 2992758.

It is an arithmetic number, because the mean of its divisors is an integer number (2098463328).

Almost surely, 2^20894951865 is an apocalyptic number.

It is an amenable number.

20894951865 is a deficient number, since it is larger than the sum of its proper divisors (12680461383).

20894951865 is a wasteful number, since it uses less digits than its factorization.

20894951865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5978768.

The product of its (nonzero) digits is 6220800, while the sum is 57.

The spelling of 20894951865 in words is "twenty billion, eight hundred ninety-four million, nine hundred fifty-one thousand, eight hundred sixty-five".