20987857149 has 16 divisors (see below), whose sum is σ = 32005038720. Its totient is φ = 11984232960.

The previous prime is 20987857147. The next prime is 20987857153. The reversal of 20987857149 is 94175878902.

It is not a de Polignac number, because 20987857149 - 2¹ = 20987857147 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20987857092 and 20987857101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20987857147) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 338584 + ... + 395745.

It is an arithmetic number, because the mean of its divisors is an integer number (2000314920).

Almost surely, 2^20987857149 is an apocalyptic number.

It is an amenable number.

20987857149 is a deficient number, since it is larger than the sum of its proper divisors (11017181571).

20987857149 is a wasteful number, since it uses less digits than its factorization.

20987857149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 735700.

The product of its (nonzero) digits is 10160640, while the sum is 60.

The spelling of 20987857149 in words is "twenty billion, nine hundred eighty-seven million, eight hundred fifty-seven thousand, one hundred forty-nine".