21531402748615 has 8 divisors (see below), whose sum is σ = 25837710459120. Its totient is φ = 17225104091712.

The previous prime is 21531402748519. The next prime is 21531402748631. The reversal of 21531402748615 is 51684720413512.

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

It is a cyclic number.

It is not a de Polignac number, because 21531402748615 - 2⁷ = 21531402748487 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5214892 + ... + 8381998.

It is an arithmetic number, because the mean of its divisors is an integer number (3229713807390).

Almost surely, 2^{21531402748615} is an apocalyptic number.

21531402748615 is a deficient number, since it is larger than the sum of its proper divisors (4306307710505).

21531402748615 is a wasteful number, since it uses less digits than its factorization.

21531402748615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4526801.

The product of its (nonzero) digits is 1612800, while the sum is 49.

The spelling of 21531402748615 in words is "twenty-one trillion, five hundred thirty-one billion, four hundred two million, seven hundred forty-eight thousand, six hundred fifteen".