21356147555015 has 16 divisors (see below), whose sum is σ = 31541387158848. Its totient is φ = 13517737353216.

The previous prime is 21356147554967. The next prime is 21356147555069. The reversal of 21356147555015 is 51055574165312.

It is a cyclic number.

It is not a de Polignac number, because 21356147555015 - 2¹⁰ = 21356147553991 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23468293562 + ... + 23468294471.

It is an arithmetic number, because the mean of its divisors is an integer number (1971336697428).

Almost surely, 2^{21356147555015} is an apocalyptic number.

21356147555015 is a deficient number, since it is larger than the sum of its proper divisors (10185239603833).

21356147555015 is a wasteful number, since it uses less digits than its factorization.

21356147555015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46936588058.

The product of its (nonzero) digits is 3150000, while the sum is 50.

The spelling of 21356147555015 in words is "twenty-one trillion, three hundred fifty-six billion, one hundred forty-seven million, five hundred fifty-five thousand, fifteen".