21263031376 has 10 divisors (see below), whose sum is σ = 41197123322. Its totient is φ = 10631515680.

The previous prime is 21263031353. The next prime is 21263031379. The reversal of 21263031376 is 67313036212.

It can be written as a sum of positive squares in only one way, i.e., 10883496976 + 10379534400 = 104324^2 + 101880^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21263031379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 664469715 + ... + 664469746.

Almost surely, 2^21263031376 is an apocalyptic number.

It is an amenable number.

21263031376 is a deficient number, since it is larger than the sum of its proper divisors (19934091946).

21263031376 is a wasteful number, since it uses less digits than its factorization.

21263031376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328939469 (or 1328939463 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 34.

Adding to 21263031376 its reverse (67313036212), we get a palindrome (88576067588).

The spelling of 21263031376 in words is "twenty-one billion, two hundred sixty-three million, thirty-one thousand, three hundred seventy-six".