21023123401 has 16 divisors (see below), whose sum is σ = 26106818560. Its totient is φ = 16520714640.

The previous prime is 21023123399. The next prime is 21023123411. The reversal of 21023123401 is 10432132012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21023123401 - 2¹ = 21023123399 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21023123411) 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, 2545371 + ... + 2553616.

It is an arithmetic number, because the mean of its divisors is an integer number (1631676160).

Almost surely, 2^21023123401 is an apocalyptic number.

It is an amenable number.

21023123401 is a deficient number, since it is larger than the sum of its proper divisors (5083695159).

21023123401 is a wasteful number, since it uses less digits than its factorization.

21023123401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5099044.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21023123401 its reverse (10432132012), we get a palindrome (31455255413).

The spelling of 21023123401 in words is "twenty-one billion, twenty-three million, one hundred twenty-three thousand, four hundred one".