13947506921 has 8 divisors (see below), whose sum is σ = 14046669000. Its totient is φ = 13848419200.

The previous prime is 13947506917. The next prime is 13947506927. The reversal of 13947506921 is 12960574931.

It can be written as a sum of positive squares in 4 ways, for example, as 714225625 + 13233281296 = 26725^2 + 115036^2 .

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 13947506921 - 2² = 13947506917 is a prime.

It is a super-2 number, since 2×13947506921² (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 (13947506927) 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, 389471 + ... + 423771.

It is an arithmetic number, because the mean of its divisors is an integer number (1755833625).

Almost surely, 2^13947506921 is an apocalyptic number.

It is an amenable number.

13947506921 is a deficient number, since it is larger than the sum of its proper divisors (99162079).

13947506921 is a wasteful number, since it uses less digits than its factorization.

13947506921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37179.

The product of its (nonzero) digits is 408240, while the sum is 47.

The spelling of 13947506921 in words is "thirteen billion, nine hundred forty-seven million, five hundred six thousand, nine hundred twenty-one".