1918431 has 16 divisors (see below), whose sum is σ = 2913120. Its totient is φ = 1247040.

The previous prime is 1918429. The next prime is 1918439. The reversal of 1918431 is 1348191.

It is not a de Polignac number, because 1918431 - 2¹ = 1918429 is a prime.

It is a super-2 number, since 2×1918431² = 7360755003522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 1918395 and 1918404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1918439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 241 + ... + 1973.

It is an arithmetic number, because the mean of its divisors is an integer number (182070).

2^1918431 is an apocalyptic number.

1918431 is a deficient number, since it is larger than the sum of its proper divisors (994689).

1918431 is a wasteful number, since it uses less digits than its factorization.

1918431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1783 (or 1777 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 1918431 is about 1385.0743662345. The cubic root of 1918431 is about 124.2554351242.

It can be divided in two parts, 191843 and 1, that added together give a square (191844 = 438²).

The spelling of 1918431 in words is "one million, nine hundred eighteen thousand, four hundred thirty-one".