1912391 has 4 divisors (see below), whose sum is σ = 2059512. Its totient is φ = 1765272.

The previous prime is 1912387. The next prime is 1912423. The reversal of 1912391 is 1932191.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1932191 = 59 ⋅32749.

It is a cyclic number.

It is not a de Polignac number, because 1912391 - 2² = 1912387 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1912391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1912301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73541 + ... + 73566.

It is an arithmetic number, because the mean of its divisors is an integer number (514878).

2^1912391 is an apocalyptic number.

1912391 is a deficient number, since it is larger than the sum of its proper divisors (147121).

1912391 is a wasteful number, since it uses less digits than its factorization.

1912391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147120.

The product of its digits is 486, while the sum is 26.

The square root of 1912391 is about 1382.8922589992. The cubic root of 1912391 is about 124.1248958384.

The spelling of 1912391 in words is "one million, nine hundred twelve thousand, three hundred ninety-one".