20423445404251 has 16 divisors (see below), whose sum is σ = 20520603721728. Its totient is φ = 20326472824000.

The previous prime is 20423445404231. The next prime is 20423445404267. The reversal of 20423445404251 is 15240454432402.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20423445404251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20423445404231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1218356196 + ... + 1218372958.

It is an arithmetic number, because the mean of its divisors is an integer number (1282537732608).

Almost surely, 2^{20423445404251} is an apocalyptic number.

20423445404251 is a deficient number, since it is larger than the sum of its proper divisors (97158317477).

20423445404251 is a wasteful number, since it uses less digits than its factorization.

20423445404251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21962.

The product of its (nonzero) digits is 614400, while the sum is 40.

Adding to 20423445404251 its reverse (15240454432402), we get a palindrome (35663899836653).

The spelling of 20423445404251 in words is "twenty trillion, four hundred twenty-three billion, four hundred forty-five million, four hundred four thousand, two hundred fifty-one".