21142431321 has 16 divisors (see below), whose sum is σ = 30755505600. Its totient is φ = 12812395520.

The previous prime is 21142431313. The next prime is 21142431329. The reversal of 21142431321 is 12313424112.

It is an interprime number because it is at equal distance from previous prime (21142431313) and next prime (21142431329).

It is a cyclic number.

It is not a de Polignac number, because 21142431321 - 2³ = 21142431313 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21142431291 and 21142431300.

It is not an unprimeable number, because it can be changed into a prime (21142431329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 436105 + ... + 482153.

It is an arithmetic number, because the mean of its divisors is an integer number (1922219100).

Almost surely, 2^21142431321 is an apocalyptic number.

It is an amenable number.

21142431321 is a deficient number, since it is larger than the sum of its proper divisors (9613074279).

21142431321 is a wasteful number, since it uses less digits than its factorization.

21142431321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59976.

The product of its digits is 1152, while the sum is 24.

Adding to 21142431321 its reverse (12313424112), we get a palindrome (33455855433).

The spelling of 21142431321 in words is "twenty-one billion, one hundred forty-two million, four hundred thirty-one thousand, three hundred twenty-one".