21240130123 has 16 divisors (see below), whose sum is σ = 22715476704. Its totient is φ = 19790149120.

The previous prime is 21240130117. The next prime is 21240130133. The reversal of 21240130123 is 32103104212.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21240130123 is a prime.

It is a super-2 number, since 2×21240130123² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21240130123.

It is not an unprimeable number, because it can be changed into a prime (21240130103) 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, 3411153 + ... + 3417373.

It is an arithmetic number, because the mean of its divisors is an integer number (1419717294).

Almost surely, 2^21240130123 is an apocalyptic number.

21240130123 is a deficient number, since it is larger than the sum of its proper divisors (1475346581).

21240130123 is a wasteful number, since it uses less digits than its factorization.

21240130123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8222.

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

Adding to 21240130123 its reverse (32103104212), we get a palindrome (53343234335).

The spelling of 21240130123 in words is "twenty-one billion, two hundred forty million, one hundred thirty thousand, one hundred twenty-three".