21245031433 has 4 divisors (see below), whose sum is σ = 21246779520. Its totient is φ = 21243283348.

The previous prime is 21245031361. The next prime is 21245031641. The reversal of 21245031433 is 33413054212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21245031433 - 2¹⁷ = 21244900361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21245031233) 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, 855685 + ... + 880162.

It is an arithmetic number, because the mean of its divisors is an integer number (5311694880).

Almost surely, 2^21245031433 is an apocalyptic number.

It is an amenable number.

21245031433 is a deficient number, since it is larger than the sum of its proper divisors (1748087).

21245031433 is a wasteful number, since it uses less digits than its factorization.

21245031433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1748086.

The product of its (nonzero) digits is 8640, while the sum is 28.

Adding to 21245031433 its reverse (33413054212), we get a palindrome (54658085645).

The spelling of 21245031433 in words is "twenty-one billion, two hundred forty-five million, thirty-one thousand, four hundred thirty-three".