21002231234 has 4 divisors (see below), whose sum is σ = 31503346854. Its totient is φ = 10501115616.

The previous prime is 21002231231. The next prime is 21002231249. The reversal of 21002231234 is 43213220012.

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

It can be written as a sum of positive squares in only one way, i.e., 20966171209 + 36060025 = 144797^2 + 6005^2 .

It is not an unprimeable number, because it can be changed into a prime (21002231231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250557807 + ... + 5250557810.

Almost surely, 2^21002231234 is an apocalyptic number.

21002231234 is a deficient number, since it is larger than the sum of its proper divisors (10501115620).

21002231234 is a wasteful number, since it uses less digits than its factorization.

21002231234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10501115619.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21002231234 its reverse (43213220012), we get a palindrome (64215451246).

The spelling of 21002231234 in words is "twenty-one billion, two million, two hundred thirty-one thousand, two hundred thirty-four".