20421252651 has 16 divisors (see below), whose sum is σ = 27950735360. Its totient is φ = 13257691200.

The previous prime is 20421252647. The next prime is 20421252671. The reversal of 20421252651 is 15625212402.

It is not a de Polignac number, because 20421252651 - 2² = 20421252647 is a prime.

It is a super-3 number, since 3×20421252651³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20421252671) 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, 572875 + ... + 607476.

It is an arithmetic number, because the mean of its divisors is an integer number (1746920960).

Almost surely, 2^20421252651 is an apocalyptic number.

20421252651 is a deficient number, since it is larger than the sum of its proper divisors (7529482709).

20421252651 is a wasteful number, since it uses less digits than its factorization.

20421252651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1180506.

The product of its (nonzero) digits is 9600, while the sum is 30.

The spelling of 20421252651 in words is "twenty billion, four hundred twenty-one million, two hundred fifty-two thousand, six hundred fifty-one".