1421820 has 48 divisors (see below), whose sum is σ = 4425120. Its totient is φ = 379008.

The previous prime is 1421813. The next prime is 1421857. The reversal of 1421820 is 281241.

It is a super-2 number, since 2×1421820² = 4043144224800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1421793 and 1421802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 777 + ... + 1856.

It is an arithmetic number, because the mean of its divisors is an integer number (92190).

2^1421820 is an apocalyptic number.

1421820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1421820 is an abundant number, since it is smaller than the sum of its proper divisors (3003300).

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

1421820 is a wasteful number, since it uses less digits than its factorization.

1421820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2651 (or 2643 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1421820 is about 1192.4009392818. The cubic root of 1421820 is about 112.4470862273.

It can be divided in two parts, 1 and 421820, that added together give a triangular number (421821 = T₉₁₈).

The spelling of 1421820 in words is "one million, four hundred twenty-one thousand, eight hundred twenty".