21035223231 has 8 divisors (see below), whose sum is σ = 30596688384. Its totient is φ = 12748620120.

The previous prime is 21035223221. The next prime is 21035223281. The reversal of 21035223231 is 13232253012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21035223231 - 2¹¹ = 21035221183 is a prime.

It is a super-2 number, since 2×21035223231² (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 (21035223221) 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, 318715471 + ... + 318715536.

It is an arithmetic number, because the mean of its divisors is an integer number (3824586048).

Almost surely, 2^21035223231 is an apocalyptic number.

21035223231 is a deficient number, since it is larger than the sum of its proper divisors (9561465153).

21035223231 is a wasteful number, since it uses less digits than its factorization.

21035223231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637431021.

The product of its (nonzero) digits is 2160, while the sum is 24.

Adding to 21035223231 its reverse (13232253012), we get a palindrome (34267476243).

The spelling of 21035223231 in words is "twenty-one billion, thirty-five million, two hundred twenty-three thousand, two hundred thirty-one".