13861398640 has 40 divisors (see below), whose sum is σ = 32773996080. Its totient is φ = 5450582016.

The previous prime is 13861398637. The next prime is 13861398641. The reversal of 13861398640 is 4689316831.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13861398641) 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, 1463649 + ... + 1473088.

It is an arithmetic number, because the mean of its divisors is an integer number (819349902).

Almost surely, 2^13861398640 is an apocalyptic number.

13861398640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13861398640 is an abundant number, since it is smaller than the sum of its proper divisors (18912597440).

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

13861398640 is a wasteful number, since it uses less digits than its factorization.

13861398640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2936809 (or 2936803 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 49.

The spelling of 13861398640 in words is "thirteen billion, eight hundred sixty-one million, three hundred ninety-eight thousand, six hundred forty".