1243021690 has 16 divisors (see below), whose sum is σ = 2285044992. Its totient is φ = 486629584.

The previous prime is 1243021679. The next prime is 1243021699. The reversal of 1243021690 is 961203421.

It is a super-2 number, since 2×1243021690² = 3090205843620912200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1243021699) 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 7 ways as a sum of consecutive naturals, for example, 1321894 + ... + 1322833.

It is an arithmetic number, because the mean of its divisors is an integer number (142815312).

Almost surely, 2^1243021690 is an apocalyptic number.

1243021690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1243021690 is a deficient number, since it is larger than the sum of its proper divisors (1042023302).

1243021690 is a wasteful number, since it uses less digits than its factorization.

1243021690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2644781.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 1243021690 is about 35256.5127316926. The cubic root of 1243021690 is about 1075.2090280388.

The spelling of 1243021690 in words is "one billion, two hundred forty-three million, twenty-one thousand, six hundred ninety".