2191636 has 6 divisors (see below), whose sum is σ = 3835370. Its totient is φ = 1095816.

The previous prime is 2191633. The next prime is 2191687. The reversal of 2191636 is 6361912.

It can be written as a sum of positive squares in only one way, i.e., 1392400 + 799236 = 1180^2 + 894^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 273951 + ... + 273958.

2^2191636 is an apocalyptic number.

It is an amenable number.

2191636 is a deficient number, since it is larger than the sum of its proper divisors (1643734).

2191636 is a wasteful number, since it uses less digits than its factorization.

2191636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547913 (or 547911 counting only the distinct ones).

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

The square root of 2191636 is about 1480.4175086779. The cubic root of 2191636 is about 129.8941149635.

It can be divided in two parts, 21916 and 36, that added together give a cube (21952 = 28³).

The spelling of 2191636 in words is "two million, one hundred ninety-one thousand, six hundred thirty-six".