23001220021 has 4 divisors (see below), whose sum is σ = 24770544652. Its totient is φ = 21231895392.

The previous prime is 23001220019. The next prime is 23001220069. The reversal of 23001220021 is 12002210032.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1723163121 + 21278056900 = 41511^2 + 145870^2 .

It is a cyclic number.

It is not a de Polignac number, because 23001220021 - 2¹ = 23001220019 is a prime.

It is a super-2 number, since 2×23001220021² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1769324617 = 23001220021 / (2 + 3 + 0 + 0 + 1 + 2 + 2 + 0 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23001219983 and 23001220010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23001220721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 884662296 + ... + 884662321.

It is an arithmetic number, because the mean of its divisors is an integer number (6192636163).

Almost surely, 2^23001220021 is an apocalyptic number.

It is an amenable number.

23001220021 is a deficient number, since it is larger than the sum of its proper divisors (1769324631).

23001220021 is a wasteful number, since it uses less digits than its factorization.

23001220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1769324630.

The product of its (nonzero) digits is 48, while the sum is 13.

Adding to 23001220021 its reverse (12002210032), we get a palindrome (35003430053).

The spelling of 23001220021 in words is "twenty-three billion, one million, two hundred twenty thousand, twenty-one".