1920391 has 12 divisors (see below), whose sum is σ = 2154600. Its totient is φ = 1709840.

The previous prime is 1920383. The next prime is 1920397. The reversal of 1920391 is 1930291.

It is not a de Polignac number, because 1920391 - 2³ = 1920383 is a prime.

It is a Duffinian number.

1920391 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1920397) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7005 + ... + 7273.

It is an arithmetic number, because the mean of its divisors is an integer number (179550).

2^1920391 is an apocalyptic number.

1920391 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1920391 is a deficient number, since it is larger than the sum of its proper divisors (234209).

1920391 is a wasteful number, since it uses less digits than its factorization.

1920391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350 (or 339 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 1920391 is about 1385.7817288448. The cubic root of 1920391 is about 124.2977366649.

The spelling of 1920391 in words is "one million, nine hundred twenty thousand, three hundred ninety-one".