1243990 has 32 divisors (see below), whose sum is σ = 2509056. Its totient is φ = 440160.

The previous prime is 1243969. The next prime is 1243997. The reversal of 1243990 is 993421.

It is a happy number.

It is a super-2 number, since 2×1243990² = 3095022240200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243997) by changing a digit.

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, 4599 + ... + 4861.

It is an arithmetic number, because the mean of its divisors is an integer number (78408).

2^1243990 is an apocalyptic number.

1243990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1243990 is an abundant number, since it is smaller than the sum of its proper divisors (1265066).

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

1243990 is a wasteful number, since it uses less digits than its factorization.

1243990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 1243990 is about 1115.3429965710. The cubic root of 1243990 is about 107.5488150394.

It can be divided in two parts, 124 and 3990, that added together give a palindrome (4114).

The spelling of 1243990 in words is "one million, two hundred forty-three thousand, nine hundred ninety".