21002120223 has 32 divisors (see below), whose sum is σ = 32503680000. Its totient is φ = 11814974976.

The previous prime is 21002120213. The next prime is 21002120257. The reversal of 21002120223 is 32202120012.

It is a happy number.

It is not a de Polignac number, because 21002120223 - 2⁸ = 21002119967 is a prime.

It is a super-2 number, since 2×21002120223² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002120213) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 323878 + ... + 383276.

It is an arithmetic number, because the mean of its divisors is an integer number (1015740000).

Almost surely, 2^21002120223 is an apocalyptic number.

21002120223 is a deficient number, since it is larger than the sum of its proper divisors (11501559777).

21002120223 is a wasteful number, since it uses less digits than its factorization.

21002120223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59671.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21002120223 its reverse (32202120012), we get a palindrome (53204240235).

The spelling of 21002120223 in words is "twenty-one billion, two million, one hundred twenty thousand, two hundred twenty-three".