21540212263 has 8 divisors (see below), whose sum is σ = 22234684032. Its totient is φ = 20851651296.

The previous prime is 21540212257. The next prime is 21540212303. The reversal of 21540212263 is 36221204512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21540212263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21540212203) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1470295 + ... + 1484872.

It is an arithmetic number, because the mean of its divisors is an integer number (2779335504).

Almost surely, 2^21540212263 is an apocalyptic number.

21540212263 is a deficient number, since it is larger than the sum of its proper divisors (694471769).

21540212263 is a wasteful number, since it uses less digits than its factorization.

21540212263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2955401.

The product of its (nonzero) digits is 5760, while the sum is 28.

Adding to 21540212263 its reverse (36221204512), we get a palindrome (57761416775).

The spelling of 21540212263 in words is "twenty-one billion, five hundred forty million, two hundred twelve thousand, two hundred sixty-three".