21144155479 has 2 divisors, whose sum is σ = 21144155480. Its totient is φ = 21144155478.

The previous prime is 21144155447. The next prime is 21144155533. The reversal of 21144155479 is 97455144112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21144155479 - 2⁵ = 21144155447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21144155419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10572077739 + 10572077740.

It is an arithmetic number, because the mean of its divisors is an integer number (10572077740).

Almost surely, 2^21144155479 is an apocalyptic number.

21144155479 is a deficient number, since it is larger than the sum of its proper divisors (1).

21144155479 is an equidigital number, since it uses as much as digits as its factorization.

21144155479 is an evil number, because the sum of its binary digits is even.

The product of its digits is 201600, while the sum is 43.

The spelling of 21144155479 in words is "twenty-one billion, one hundred forty-four million, one hundred fifty-five thousand, four hundred seventy-nine".