10521405561 has 4 divisors (see below), whose sum is σ = 14028540752. Its totient is φ = 7014270372.

The previous prime is 10521405533. The next prime is 10521405617. The reversal of 10521405561 is 16550412501.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 10521405561 - 2¹⁸ = 10521143417 is a prime.

It is a super-2 number, since 2×10521405561² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10521405511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1753567591 + ... + 1753567596.

It is an arithmetic number, because the mean of its divisors is an integer number (3507135188).

Almost surely, 2^10521405561 is an apocalyptic number.

It is an amenable number.

10521405561 is a deficient number, since it is larger than the sum of its proper divisors (3507135191).

10521405561 is an equidigital number, since it uses as much as digits as its factorization.

10521405561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3507135190.

The product of its (nonzero) digits is 6000, while the sum is 30.

The spelling of 10521405561 in words is "ten billion, five hundred twenty-one million, four hundred five thousand, five hundred sixty-one".