20000021231 has 2 divisors, whose sum is σ = 20000021232. Its totient is φ = 20000021230.

The previous prime is 20000021221. The next prime is 20000021267. The reversal of 20000021231 is 13212000002.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20000021231 - 2²⁶ = 19932912367 is a prime.

It is a super-2 number, since 2×20000021231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20000021201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000010615 + 10000010616.

It is an arithmetic number, because the mean of its divisors is an integer number (10000010616).

Almost surely, 2^20000021231 is an apocalyptic number.

20000021231 is a deficient number, since it is larger than the sum of its proper divisors (1).

20000021231 is an equidigital number, since it uses as much as digits as its factorization.

20000021231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 11.

Adding to 20000021231 its reverse (13212000002), we get a palindrome (33212021233).

The spelling of 20000021231 in words is "twenty billion, twenty-one thousand, two hundred thirty-one".