1921636 has 6 divisors (see below), whose sum is σ = 3362870. Its totient is φ = 960816.

The previous prime is 1921631. The next prime is 1921657. The reversal of 1921636 is 6361291.

It can be written as a sum of positive squares in only one way, i.e., 1440000 + 481636 = 1200^2 + 694^2 .

It is not an unprimeable number, because it can be changed into a prime (1921631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 240201 + ... + 240208.

2^1921636 is an apocalyptic number.

It is an amenable number.

1921636 is a deficient number, since it is larger than the sum of its proper divisors (1441234).

1921636 is a wasteful number, since it uses less digits than its factorization.

1921636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480413 (or 480411 counting only the distinct ones).

The product of its digits is 1944, while the sum is 28.

The square root of 1921636 is about 1386.2308610040. The cubic root of 1921636 is about 124.3245918300.

The spelling of 1921636 in words is "one million, nine hundred twenty-one thousand, six hundred thirty-six".