13890837778 has 4 divisors (see below), whose sum is σ = 20836256670. Its totient is φ = 6945418888.

The previous prime is 13890837769. The next prime is 13890837791. The reversal of 13890837778 is 87773809831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87773809831 = 8081 ⋅10861751.

It can be written as a sum of positive squares in only one way, i.e., 12618702889 + 1272134889 = 112333^2 + 35667^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3472709443 + ... + 3472709446.

Almost surely, 2^13890837778 is an apocalyptic number.

13890837778 is a deficient number, since it is larger than the sum of its proper divisors (6945418892).

13890837778 is an equidigital number, since it uses as much as digits as its factorization.

13890837778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6945418891.

The product of its (nonzero) digits is 14224896, while the sum is 61.

The spelling of 13890837778 in words is "thirteen billion, eight hundred ninety million, eight hundred thirty-seven thousand, seven hundred seventy-eight".