20621163251 has 8 divisors (see below), whose sum is σ = 23513724864. Its totient is φ = 17915218560.

The previous prime is 20621163247. The next prime is 20621163253. The reversal of 20621163251 is 15236112602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20621163251 - 2² = 20621163247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20621163253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46653995 + ... + 46654436.

It is an arithmetic number, because the mean of its divisors is an integer number (2939215608).

Almost surely, 2^20621163251 is an apocalyptic number.

20621163251 is a deficient number, since it is larger than the sum of its proper divisors (2892561613).

20621163251 is a wasteful number, since it uses less digits than its factorization.

20621163251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93308461.

The product of its (nonzero) digits is 4320, while the sum is 29.

Adding to 20621163251 its reverse (15236112602), we get a palindrome (35857275853).

The spelling of 20621163251 in words is "twenty billion, six hundred twenty-one million, one hundred sixty-three thousand, two hundred fifty-one".