21312025451 has 2 divisors, whose sum is σ = 21312025452. Its totient is φ = 21312025450.

The previous prime is 21312025447. The next prime is 21312025477. The reversal of 21312025451 is 15452021312.

It is an a-pointer prime, because the next prime (21312025477) can be obtained adding 21312025451 to its sum of digits (26).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21312025451 - 2² = 21312025447 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21312025451.

It is not a weakly prime, because it can be changed into another prime (21312022451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656012725 + 10656012726.

It is an arithmetic number, because the mean of its divisors is an integer number (10656012726).

Almost surely, 2^21312025451 is an apocalyptic number.

21312025451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312025451 is an equidigital number, since it uses as much as digits as its factorization.

21312025451 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21312025451 its reverse (15452021312), we get a palindrome (36764046763).

The spelling of 21312025451 in words is "twenty-one billion, three hundred twelve million, twenty-five thousand, four hundred fifty-one".