21020023130 has 16 divisors (see below), whose sum is σ = 38549930184. Its totient is φ = 8249367360.

The previous prime is 21020023117. The next prime is 21020023147. The reversal of 21020023130 is 3132002012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21018330529 + 1692601 = 144977^2 + 1301^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19829681 + ... + 19830740.

Almost surely, 2^21020023130 is an apocalyptic number.

21020023130 is a deficient number, since it is larger than the sum of its proper divisors (17529907054).

21020023130 is a wasteful number, since it uses less digits than its factorization.

21020023130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39660481.

The product of its (nonzero) digits is 72, while the sum is 14.

Adding to 21020023130 its reverse (3132002012), we get a palindrome (24152025142).

The spelling of 21020023130 in words is "twenty-one billion, twenty million, twenty-three thousand, one hundred thirty".