21121450015 has 8 divisors (see below), whose sum is σ = 25405946208. Its totient is φ = 16857022560.

The previous prime is 21121449989. The next prime is 21121450043. The reversal of 21121450015 is 51005412112.

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

It is not a de Polignac number, because 21121450015 - 2¹¹ = 21121447967 is a prime.

It is a super-2 number, since 2×21121450015² (a number of 21 digits) contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 5014867 + ... + 5019076.

It is an arithmetic number, because the mean of its divisors is an integer number (3175743276).

Almost surely, 2^21121450015 is an apocalyptic number.

21121450015 is a deficient number, since it is larger than the sum of its proper divisors (4284496193).

21121450015 is a wasteful number, since it uses less digits than its factorization.

21121450015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10034369.

The product of its (nonzero) digits is 400, while the sum is 22.

Adding to 21121450015 its reverse (51005412112), we get a palindrome (72126862127).

The spelling of 21121450015 in words is "twenty-one billion, one hundred twenty-one million, four hundred fifty thousand, fifteen".