20421510849 has 12 divisors (see below), whose sum is σ = 29526362112. Its totient is φ = 13601129400.

The previous prime is 20421510847. The next prime is 20421510853. The reversal of 20421510849 is 94801512402.

20421510849 is a `hidden beast` number, since 20 + 42 + 1 + 510 + 84 + 9 = 666.

It is not a de Polignac number, because 20421510849 - 2¹ = 20421510847 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20421510847) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1091137 + ... + 1109694.

It is an arithmetic number, because the mean of its divisors is an integer number (2460530176).

Almost surely, 2^20421510849 is an apocalyptic number.

It is an amenable number.

20421510849 is a deficient number, since it is larger than the sum of its proper divisors (9104851263).

20421510849 is a wasteful number, since it uses less digits than its factorization.

20421510849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2201868 (or 2201865 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The spelling of 20421510849 in words is "twenty billion, four hundred twenty-one million, five hundred ten thousand, eight hundred forty-nine".