13401721636 has 6 divisors (see below), whose sum is σ = 23453012870. Its totient is φ = 6700860816.

The previous prime is 13401721607. The next prime is 13401721637. The reversal of 13401721636 is 63612710431.

It can be written as a sum of positive squares in only one way, i.e., 8808948736 + 4592772900 = 93856^2 + 67770^2 .

It is a super-2 number, since 2×13401721636² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (13401721637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1675215201 + ... + 1675215208.

Almost surely, 2^13401721636 is an apocalyptic number.

It is an amenable number.

13401721636 is a deficient number, since it is larger than the sum of its proper divisors (10051291234).

13401721636 is a wasteful number, since it uses less digits than its factorization.

13401721636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3350430413 (or 3350430411 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 34.

The spelling of 13401721636 in words is "thirteen billion, four hundred one million, seven hundred twenty-one thousand, six hundred thirty-six".