21124002451 has 2 divisors, whose sum is σ = 21124002452. Its totient is φ = 21124002450.

The previous prime is 21124002407. The next prime is 21124002479. The reversal of 21124002451 is 15420042112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21124002451 - 2⁷ = 21124002323 is a prime.

It is not a weakly prime, because it can be changed into another prime (21124005451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562001225 + 10562001226.

It is an arithmetic number, because the mean of its divisors is an integer number (10562001226).

Almost surely, 2^21124002451 is an apocalyptic number.

21124002451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124002451 is an equidigital number, since it uses as much as digits as its factorization.

21124002451 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 640, while the sum is 22.

Adding to 21124002451 its reverse (15420042112), we get a palindrome (36544044563).

The spelling of 21124002451 in words is "twenty-one billion, one hundred twenty-four million, two thousand, four hundred fifty-one".