21404433331 has 8 divisors (see below), whose sum is σ = 21759917760. Its totient is φ = 21051827688.

The previous prime is 21404433329. The next prime is 21404433353. The reversal of 21404433331 is 13333440412.

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

It is a cyclic number.

It is not a de Polignac number, because 21404433331 - 2¹ = 21404433329 is a prime.

It is a super-2 number, since 2×21404433331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21404433331.

It is not an unprimeable number, because it can be changed into a prime (21404433731) 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, 704701 + ... + 734446.

It is an arithmetic number, because the mean of its divisors is an integer number (2719989720).

Almost surely, 2^21404433331 is an apocalyptic number.

21404433331 is a deficient number, since it is larger than the sum of its proper divisors (355484429).

21404433331 is a wasteful number, since it uses less digits than its factorization.

21404433331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1439393.

The product of its (nonzero) digits is 10368, while the sum is 28.

Adding to 21404433331 its reverse (13333440412), we get a palindrome (34737873743).

The spelling of 21404433331 in words is "twenty-one billion, four hundred four million, four hundred thirty-three thousand, three hundred thirty-one".