13420401521 has 4 divisors (see below), whose sum is σ = 13420649472. Its totient is φ = 13420153572.

The previous prime is 13420401509. The next prime is 13420401557. The reversal of 13420401521 is 12510402431.

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 a cyclic number.

It is not a de Polignac number, because 13420401521 - 2⁶ = 13420401457 is a prime.

It is a super-2 number, since 2×13420401521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13420481521) 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, 4241 + ... + 163886.

It is an arithmetic number, because the mean of its divisors is an integer number (3355162368).

Almost surely, 2^13420401521 is an apocalyptic number.

It is an amenable number.

13420401521 is a deficient number, since it is larger than the sum of its proper divisors (247951).

13420401521 is an equidigital number, since it uses as much as digits as its factorization.

13420401521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247950.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 13420401521 its reverse (12510402431), we get a palindrome (25930803952).

The spelling of 13420401521 in words is "thirteen billion, four hundred twenty million, four hundred one thousand, five hundred twenty-one".