21231401392 has 20 divisors (see below), whose sum is σ = 41397856816. Its totient is φ = 10548083520.

The previous prime is 21231401377. The next prime is 21231401393. The reversal of 21231401392 is 29310413212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21231401392.

It is not an unprimeable number, because it can be changed into a prime (21231401393) 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, 4223484 + ... + 4228507.

Almost surely, 2^21231401392 is an apocalyptic number.

It is an amenable number.

21231401392 is a deficient number, since it is larger than the sum of its proper divisors (20166455424).

21231401392 is a wasteful number, since it uses less digits than its factorization.

21231401392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8452156 (or 8452150 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The spelling of 21231401392 in words is "twenty-one billion, two hundred thirty-one million, four hundred one thousand, three hundred ninety-two".