20000001021 has 96 divisors (see below), whose sum is σ = 36244389888. Its totient is φ = 9473345280.

The previous prime is 20000001017. The next prime is 20000001031. The reversal of 20000001021 is 12010000002.

It is a happy number.

It is not a de Polignac number, because 20000001021 - 2² = 20000001017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20000001031) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 87336135 + ... + 87336363.

It is an arithmetic number, because the mean of its divisors is an integer number (377545728).

Almost surely, 2^20000001021 is an apocalyptic number.

20000001021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20000001021 is a deficient number, since it is larger than the sum of its proper divisors (16244388867).

20000001021 is a wasteful number, since it uses less digits than its factorization.

20000001021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

Adding to 20000001021 its reverse (12010000002), we get a palindrome (32010001023).

The spelling of 20000001021 in words is "twenty billion, one thousand, twenty-one".