1605913638 has 32 divisors (see below), whose sum is σ = 3680280576. Its totient is φ = 457629888.

The previous prime is 1605913607. The next prime is 1605913651. The reversal of 1605913638 is 8363195061.

It is a happy number.

1605913638 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×1605913638² = 5157917225428790088, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 1605913638.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33831 + ... + 66002.

It is an arithmetic number, because the mean of its divisors is an integer number (115008768).

Almost surely, 2^1605913638 is an apocalyptic number.

1605913638 is an abundant number, since it is smaller than the sum of its proper divisors (2074366938).

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

1605913638 is a wasteful number, since it uses less digits than its factorization.

1605913638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100228.

The product of its (nonzero) digits is 116640, while the sum is 42.

The square root of 1605913638 is about 40073.8522979760. The cubic root of 1605913638 is about 1171.0462888417.

The spelling of 1605913638 in words is "one billion, six hundred five million, nine hundred thirteen thousand, six hundred thirty-eight".