13778021856 has 48 divisors (see below), whose sum is σ = 36175797504. Its totient is φ = 4591595904.

The previous prime is 13778021837. The next prime is 13778021879. The reversal of 13778021856 is 65812087731.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 465945 + ... + 494631.

It is an arithmetic number, because the mean of its divisors is an integer number (753662448).

Almost surely, 2^13778021856 is an apocalyptic number.

13778021856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

13778021856 is an abundant number, since it is smaller than the sum of its proper divisors (22397775648).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13778021856 is a wasteful number, since it uses less digits than its factorization.

13778021856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33703 (or 33695 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 48.

The spelling of 13778021856 in words is "thirteen billion, seven hundred seventy-eight million, twenty-one thousand, eight hundred fifty-six".