21510872343 has 24 divisors (see below), whose sum is σ = 32277432096. Its totient is φ = 13793740800.

The previous prime is 21510872333. The next prime is 21510872347. The reversal of 21510872343 is 34327801512.

21510872343 is a `hidden beast` number, since 2 + 1 + 510 + 87 + 23 + 43 = 666.

It is not a de Polignac number, because 21510872343 - 2⁸ = 21510872087 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21510872298 and 21510872307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21510872347) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 384330 + ... + 436727.

It is an arithmetic number, because the mean of its divisors is an integer number (1344893004).

Almost surely, 2^21510872343 is an apocalyptic number.

21510872343 is a deficient number, since it is larger than the sum of its proper divisors (10766559753).

21510872343 is a wasteful number, since it uses less digits than its factorization.

21510872343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821175 (or 821172 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The spelling of 21510872343 in words is "twenty-one billion, five hundred ten million, eight hundred seventy-two thousand, three hundred forty-three".