21425403123 has 16 divisors (see below), whose sum is σ = 31743619200. Its totient is φ = 14282575560.

The previous prime is 21425403119. The next prime is 21425403217. The reversal of 21425403123 is 32130452412.

21425403123 is a `hidden beast` number, since 214 + 25 + 403 + 1 + 23 = 666.

It is not a de Polignac number, because 21425403123 - 2² = 21425403119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21425402123) 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, 633988 + ... + 666926.

It is an arithmetic number, because the mean of its divisors is an integer number (1983976200).

Almost surely, 2^21425403123 is an apocalyptic number.

21425403123 is a deficient number, since it is larger than the sum of its proper divisors (10318216077).

21425403123 is a wasteful number, since it uses less digits than its factorization.

21425403123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57039 (or 57033 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 21425403123 its reverse (32130452412), we get a palindrome (53555855535).

The spelling of 21425403123 in words is "twenty-one billion, four hundred twenty-five million, four hundred three thousand, one hundred twenty-three".