1918197 has 6 divisors (see below), whose sum is σ = 2770742. Its totient is φ = 1278792.

The previous prime is 1918193. The next prime is 1918219. The reversal of 1918197 is 7918191.

It can be written as a sum of positive squares in only one way, i.e., 1454436 + 463761 = 1206^2 + 681^2 .

It is not a de Polignac number, because 1918197 - 2² = 1918193 is a prime.

It is a Duffinian number.

1918197 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1918193) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106558 + ... + 106575.

2^1918197 is an apocalyptic number.

It is an amenable number.

1918197 is a deficient number, since it is larger than the sum of its proper divisors (852545).

1918197 is a wasteful number, since it uses less digits than its factorization.

1918197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213139 (or 213136 counting only the distinct ones).

The product of its digits is 4536, while the sum is 36.

The square root of 1918197 is about 1384.9898916599. The cubic root of 1918197 is about 124.2503829133.

The spelling of 1918197 in words is "one million, nine hundred eighteen thousand, one hundred ninety-seven".