21015340235 has 32 divisors (see below), whose sum is σ = 26683914240. Its totient is φ = 15856334208.

The previous prime is 21015340217. The next prime is 21015340261. The reversal of 21015340235 is 53204351012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21015340235 - 2¹⁰ = 21015339211 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11019152 + ... + 11021058.

It is an arithmetic number, because the mean of its divisors is an integer number (833872320).

Almost surely, 2^21015340235 is an apocalyptic number.

21015340235 is a deficient number, since it is larger than the sum of its proper divisors (5668574005).

21015340235 is a wasteful number, since it uses less digits than its factorization.

21015340235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3227.

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21015340235 its reverse (53204351012), we get a palindrome (74219691247).

The spelling of 21015340235 in words is "twenty-one billion, fifteen million, three hundred forty thousand, two hundred thirty-five".