21807123130 has 16 divisors (see below), whose sum is σ = 42272269704. Its totient is φ = 8051860800.

The previous prime is 21807123103. The next prime is 21807123131. The reversal of 21807123130 is 3132170812.

It can be written as a sum of positive squares in 4 ways, for example, as 8311421889 + 13495701241 = 91167^2 + 116171^2 .

It is not an unprimeable number, because it can be changed into a prime (21807123131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83873421 + ... + 83873680.

Almost surely, 2^21807123130 is an apocalyptic number.

21807123130 is a deficient number, since it is larger than the sum of its proper divisors (20465146574).

21807123130 is a wasteful number, since it uses less digits than its factorization.

21807123130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167747121.

The product of its (nonzero) digits is 2016, while the sum is 28.

Adding to 21807123130 its reverse (3132170812), we get a palindrome (24939293942).

The spelling of 21807123130 in words is "twenty-one billion, eight hundred seven million, one hundred twenty-three thousand, one hundred thirty".