21330402431 has 24 divisors (see below), whose sum is σ = 23754140784. Its totient is φ = 19131240960.

The previous prime is 21330402409. The next prime is 21330402437. The reversal of 21330402431 is 13420403312.

It is not a de Polignac number, because 21330402431 - 2¹⁸ = 21330140287 is a prime.

It is a super-2 number, since 2×21330402431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21330402397 and 21330402406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330402437) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5669591 + ... + 5673351.

It is an arithmetic number, because the mean of its divisors is an integer number (989755866).

Almost surely, 2^21330402431 is an apocalyptic number.

21330402431 is a deficient number, since it is larger than the sum of its proper divisors (2423738353).

21330402431 is a wasteful number, since it uses less digits than its factorization.

21330402431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4731 (or 4718 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21330402431 its reverse (13420403312), we get a palindrome (34750805743).

The spelling of 21330402431 in words is "twenty-one billion, three hundred thirty million, four hundred two thousand, four hundred thirty-one".