21040123051 has 2 divisors, whose sum is σ = 21040123052. Its totient is φ = 21040123050.

The previous prime is 21040123037. The next prime is 21040123063. The reversal of 21040123051 is 15032104012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21040123051 - 2²³ = 21031734443 is a prime.

It is not a weakly prime, because it can be changed into another prime (21040183051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520061525 + 10520061526.

It is an arithmetic number, because the mean of its divisors is an integer number (10520061526).

Almost surely, 2^21040123051 is an apocalyptic number.

21040123051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21040123051 is an equidigital number, since it uses as much as digits as its factorization.

21040123051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 19.

Adding to 21040123051 its reverse (15032104012), we get a palindrome (36072227063).

The spelling of 21040123051 in words is "twenty-one billion, forty million, one hundred twenty-three thousand, fifty-one".