21141431021 has 2 divisors, whose sum is σ = 21141431022. Its totient is φ = 21141431020.

The previous prime is 21141431011. The next prime is 21141431023. The reversal of 21141431021 is 12013414112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20411836900 + 729594121 = 142870^2 + 27011^2 .

It is a cyclic number.

It is not a de Polignac number, because 21141431021 - 2¹⁸ = 21141168877 is a prime.

It is a super-2 number, since 2×21141431021² (a number of 21 digits) contains 22 as substring.

Together with 21141431023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21141430984 and 21141431002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21141431023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570715510 + 10570715511.

It is an arithmetic number, because the mean of its divisors is an integer number (10570715511).

Almost surely, 2^21141431021 is an apocalyptic number.

It is an amenable number.

21141431021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21141431021 is an equidigital number, since it uses as much as digits as its factorization.

21141431021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 21141431021 its reverse (12013414112), we get a palindrome (33154845133).

The spelling of 21141431021 in words is "twenty-one billion, one hundred forty-one million, four hundred thirty-one thousand, twenty-one".