21345840450 has 72 divisors (see below), whose sum is σ = 62562732336. Its totient is φ = 5174748000.

The previous prime is 21345840431. The next prime is 21345840487. The reversal of 21345840450 is 5404854312.

It is a happy number.

21345840450 is a `hidden beast` number, since 2 + 1 + 34 + 584 + 0 + 45 + 0 = 666.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2151196 + ... + 2161095.

It is an arithmetic number, because the mean of its divisors is an integer number (868926838).

Almost surely, 2^21345840450 is an apocalyptic number.

21345840450 is an abundant number, since it is smaller than the sum of its proper divisors (41216891886).

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

21345840450 is a wasteful number, since it uses less digits than its factorization.

21345840450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4312320 (or 4312312 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

The spelling of 21345840450 in words is "twenty-one billion, three hundred forty-five million, eight hundred forty thousand, four hundred fifty".