1638590149 has 4 divisors (see below), whose sum is σ = 1872674464. Its totient is φ = 1404505836.

The previous prime is 1638590147. The next prime is 1638590159. The reversal of 1638590149 is 9410958361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1638590149 - 2¹ = 1638590147 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1638590099 and 1638590108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638590141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117042147 + ... + 117042160.

It is an arithmetic number, because the mean of its divisors is an integer number (468168616).

Almost surely, 2^1638590149 is an apocalyptic number.

It is an amenable number.

1638590149 is a deficient number, since it is larger than the sum of its proper divisors (234084315).

1638590149 is an equidigital number, since it uses as much as digits as its factorization.

1638590149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234084314.

The product of its (nonzero) digits is 233280, while the sum is 46.

The square root of 1638590149 is about 40479.5028255042. The cubic root of 1638590149 is about 1178.9356842399.

The spelling of 1638590149 in words is "one billion, six hundred thirty-eight million, five hundred ninety thousand, one hundred forty-nine".