21505332398 has 8 divisors (see below), whose sum is σ = 35190543960. Its totient is φ = 9775151080.

The previous prime is 21505332379. The next prime is 21505332439. The reversal of 21505332398 is 89323350512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 488757533 + ... + 488757576.

It is an arithmetic number, because the mean of its divisors is an integer number (4398817995).

Almost surely, 2^21505332398 is an apocalyptic number.

21505332398 is a deficient number, since it is larger than the sum of its proper divisors (13685211562).

21505332398 is a wasteful number, since it uses less digits than its factorization.

21505332398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 977515122.

The product of its (nonzero) digits is 194400, while the sum is 41.

The spelling of 21505332398 in words is "twenty-one billion, five hundred five million, three hundred thirty-two thousand, three hundred ninety-eight".