21534215450 has 96 divisors (see below), whose sum is σ = 44295968448. Its totient is φ = 7723584000.

The previous prime is 21534215429. The next prime is 21534215473. The reversal of 21534215450 is 5451243512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16300790 + ... + 16302110.

It is an arithmetic number, because the mean of its divisors is an integer number (461416338).

Almost surely, 2^21534215450 is an apocalyptic number.

21534215450 is an abundant number, since it is smaller than the sum of its proper divisors (22761752998).

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

21534215450 is a wasteful number, since it uses less digits than its factorization.

21534215450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1728 (or 1723 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 21534215450 its reverse (5451243512), we get a palindrome (26985458962).

The spelling of 21534215450 in words is "twenty-one billion, five hundred thirty-four million, two hundred fifteen thousand, four hundred fifty".