1284390 has 64 divisors (see below), whose sum is σ = 3525120. Its totient is φ = 332640.

The previous prime is 1284383. The next prime is 1284421. The reversal of 1284390 is 934821.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18055 + ... + 18125.

It is an arithmetic number, because the mean of its divisors is an integer number (55080).

2^1284390 is an apocalyptic number.

1284390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1284390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1762560).

1284390 is an abundant number, since it is smaller than the sum of its proper divisors (2240730).

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

1284390 is a wasteful number, since it uses less digits than its factorization.

1284390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 1284390 is about 1133.3093134710. The cubic root of 1284390 is about 108.7006910823.

The spelling of 1284390 in words is "one million, two hundred eighty-four thousand, three hundred ninety".