21230013440 has 88 divisors (see below), whose sum is σ = 53923089312. Its totient is φ = 7992442880.

The previous prime is 21230013421. The next prime is 21230013461. The reversal of 21230013440 is 4431003212.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34916 + ... + 208995.

Almost surely, 2^21230013440 is an apocalyptic number.

21230013440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21230013440 is an abundant number, since it is smaller than the sum of its proper divisors (32693075872).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21230013440 is a wasteful number, since it uses less digits than its factorization.

21230013440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243953 (or 243935 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21230013440 its reverse (4431003212), we get a palindrome (25661016652).

The spelling of 21230013440 in words is "twenty-one billion, two hundred thirty million, thirteen thousand, four hundred forty".