21053001215 has 4 divisors (see below), whose sum is σ = 25263601464. Its totient is φ = 16842400968.

The previous prime is 21053001173. The next prime is 21053001241. The reversal of 21053001215 is 51210035012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21053001215 - 2¹⁰ = 21053000191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2105300117 + ... + 2105300126.

It is an arithmetic number, because the mean of its divisors is an integer number (6315900366).

Almost surely, 2^21053001215 is an apocalyptic number.

21053001215 is a deficient number, since it is larger than the sum of its proper divisors (4210600249).

21053001215 is an equidigital number, since it uses as much as digits as its factorization.

21053001215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4210600248.

The product of its (nonzero) digits is 300, while the sum is 20.

Adding to 21053001215 its reverse (51210035012), we get a palindrome (72263036227).

The spelling of 21053001215 in words is "twenty-one billion, fifty-three million, one thousand, two hundred fifteen".