21350215385 has 8 divisors (see below), whose sum is σ = 25632127176. Its totient is φ = 17072259840.

The previous prime is 21350215351. The next prime is 21350215433. The reversal of 21350215385 is 58351205312.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3638864329 + 17711351056 = 60323^2 + 133084^2 .

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

It is not a de Polignac number, because 21350215385 - 2¹⁸ = 21349953241 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 977174 + ... + 998783.

It is an arithmetic number, because the mean of its divisors is an integer number (3204015897).

Almost surely, 2^21350215385 is an apocalyptic number.

It is an amenable number.

21350215385 is a deficient number, since it is larger than the sum of its proper divisors (4281911791).

21350215385 is a wasteful number, since it uses less digits than its factorization.

21350215385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1978123.

The product of its (nonzero) digits is 36000, while the sum is 35.

The spelling of 21350215385 in words is "twenty-one billion, three hundred fifty million, two hundred fifteen thousand, three hundred eighty-five".