13961640 has 128 divisors (see below), whose sum is σ = 52254720. Its totient is φ = 2899200.

The previous prime is 13961639. The next prime is 13961657. The reversal of 13961640 is 4616931.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 13961598 and 13961607.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8485 + ... + 9995.

It is an arithmetic number, because the mean of its divisors is an integer number (408240).

Almost surely, 2^13961640 is an apocalyptic number.

13961640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13961640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26127360).

13961640 is an abundant number, since it is smaller than the sum of its proper divisors (38293080).

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

13961640 is a wasteful number, since it uses less digits than its factorization.

13961640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1543 (or 1539 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 13961640 is about 3736.5277999769. The cubic root of 13961640 is about 240.7938987354.

It can be divided in two parts, 139616 and 40, that added together give a triangular number (139656 = T₅₂₈).

The spelling of 13961640 in words is "thirteen million, nine hundred sixty-one thousand, six hundred forty".