10515421721 has 16 divisors (see below), whose sum is σ = 12458759040. Its totient is φ = 8683704960.

The previous prime is 10515421691. The next prime is 10515421747. The reversal of 10515421721 is 12712451501.

It is not a de Polignac number, because 10515421721 - 2¹⁴ = 10515405337 is a prime.

It is a super-2 number, since 2×10515421721² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is not an unprimeable number, because it can be changed into a prime (10515421751) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39341 + ... + 150261.

It is an arithmetic number, because the mean of its divisors is an integer number (778672440).

Almost surely, 2^10515421721 is an apocalyptic number.

It is an amenable number.

10515421721 is a deficient number, since it is larger than the sum of its proper divisors (1943337319).

10515421721 is a wasteful number, since it uses less digits than its factorization.

10515421721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111424.

The product of its (nonzero) digits is 2800, while the sum is 29.

The spelling of 10515421721 in words is "ten billion, five hundred fifteen million, four hundred twenty-one thousand, seven hundred twenty-one".