2138693544 has 128 divisors (see below), whose sum is σ = 6477475200. Its totient is φ = 657989568.

The previous prime is 2138693521. The next prime is 2138693569. The reversal of 2138693544 is 4453968312.

2138693544 is a `hidden beast` number, since 2 + 13 + 8 + 6 + 93 + 544 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 2138693544.

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, 222747 + ... + 232149.

It is an arithmetic number, because the mean of its divisors is an integer number (50605275).

Almost surely, 2^2138693544 is an apocalyptic number.

2138693544 is a gapful number since it is divisible by the number (24) 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 2138693544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3238737600).

2138693544 is an abundant number, since it is smaller than the sum of its proper divisors (4338781656).

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

2138693544 is an equidigital number, since it uses as much as digits as its factorization.

2138693544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9443 (or 9421 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The square root of 2138693544 is about 46246.0111144734. The cubic root of 2138693544 is about 1288.3964499149.

The spelling of 2138693544 in words is "two billion, one hundred thirty-eight million, six hundred ninety-three thousand, five hundred forty-four".