21220453015 has 4 divisors (see below), whose sum is σ = 25464543624. Its totient is φ = 16976362408.

The previous prime is 21220453013. The next prime is 21220453049. The reversal of 21220453015 is 51035402212.

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 21220453015 - 2¹ = 21220453013 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 (21220453013) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2122045297 + ... + 2122045306.

It is an arithmetic number, because the mean of its divisors is an integer number (6366135906).

Almost surely, 2^21220453015 is an apocalyptic number.

21220453015 is a deficient number, since it is larger than the sum of its proper divisors (4244090609).

21220453015 is an equidigital number, since it uses as much as digits as its factorization.

21220453015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4244090608.

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 21220453015 its reverse (51035402212), we get a palindrome (72255855227).

The spelling of 21220453015 in words is "twenty-one billion, two hundred twenty million, four hundred fifty-three thousand, fifteen".