1421840 has 40 divisors (see below), whose sum is σ = 3779520. Its totient is φ = 487296.

The previous prime is 1421813. The next prime is 1421857. The reversal of 1421840 is 481241.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 710 + ... + 1829.

It is an arithmetic number, because the mean of its divisors is an integer number (94488).

2^1421840 is an apocalyptic number.

1421840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1421840 is an abundant number, since it is smaller than the sum of its proper divisors (2357680).

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

1421840 is a wasteful number, since it uses less digits than its factorization.

1421840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2559 (or 2553 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 1421840 is about 1192.4093256932. The cubic root of 1421840 is about 112.4476134697.

The spelling of 1421840 in words is "one million, four hundred twenty-one thousand, eight hundred forty".