11421506521 has 8 divisors (see below), whose sum is σ = 11499451200. Its totient is φ = 11343719280.

The previous prime is 11421506501. The next prime is 11421506573. The reversal of 11421506521 is 12560512411.

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

It is a cyclic number.

It is not a de Polignac number, because 11421506521 - 2¹⁹ = 11420982233 is a prime.

It is a super-2 number, since 2×11421506521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11421506521.

It is not an unprimeable number, because it can be changed into a prime (11421506501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 108100 + ... + 185818.

It is an arithmetic number, because the mean of its divisors is an integer number (1437431400).

Almost surely, 2^11421506521 is an apocalyptic number.

It is an amenable number.

11421506521 is a deficient number, since it is larger than the sum of its proper divisors (77944679).

11421506521 is an equidigital number, since it uses as much as digits as its factorization.

11421506521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78719.

The product of its (nonzero) digits is 2400, while the sum is 28.

The spelling of 11421506521 in words is "eleven billion, four hundred twenty-one million, five hundred six thousand, five hundred twenty-one".