21421121149 has 2 divisors, whose sum is σ = 21421121150. Its totient is φ = 21421121148.

The previous prime is 21421121147. The next prime is 21421121171. The reversal of 21421121149 is 94112112412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18709315524 + 2711805625 = 136782^2 + 52075^2 .

It is a cyclic number.

It is not a de Polignac number, because 21421121149 - 2¹ = 21421121147 is a prime.

Together with 21421121147, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21421121143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710560574 + 10710560575.

It is an arithmetic number, because the mean of its divisors is an integer number (10710560575).

Almost surely, 2^21421121149 is an apocalyptic number.

It is an amenable number.

21421121149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421121149 is an equidigital number, since it uses as much as digits as its factorization.

21421121149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 28.

The spelling of 21421121149 in words is "twenty-one billion, four hundred twenty-one million, one hundred twenty-one thousand, one hundred forty-nine".