21323431240 has 32 divisors (see below), whose sum is σ = 48016805760. Its totient is φ = 8522424000.

The previous prime is 21323431231. The next prime is 21323431243. The reversal of 21323431240 is 4213432312.

It is not an unprimeable number, because it can be changed into a prime (21323431243) 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, 167286 + ... + 265765.

It is an arithmetic number, because the mean of its divisors is an integer number (1500525180).

Almost surely, 2^21323431240 is an apocalyptic number.

21323431240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21323431240 is an abundant number, since it is smaller than the sum of its proper divisors (26693374520).

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

21323431240 is a wasteful number, since it uses less digits than its factorization.

21323431240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434293 (or 434289 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21323431240 its reverse (4213432312), we get a palindrome (25536863552).

The spelling of 21323431240 in words is "twenty-one billion, three hundred twenty-three million, four hundred thirty-one thousand, two hundred forty".