1921428 has 24 divisors (see below), whose sum is σ = 4981760. Its totient is φ = 640440.

The previous prime is 1921427. The next prime is 1921457. The reversal of 1921428 is 8241291.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8788 + ... + 9003.

2^1921428 is an apocalyptic number.

1921428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1921428 is an abundant number, since it is smaller than the sum of its proper divisors (3060332).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1921428 is a wasteful number, since it uses less digits than its factorization.

1921428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17804 (or 17796 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 1921428 is about 1386.1558353951. The cubic root of 1921428 is about 124.3201059912.

The spelling of 1921428 in words is "one million, nine hundred twenty-one thousand, four hundred twenty-eight".