1639243990 has 16 divisors (see below), whose sum is σ = 2952531648. Its totient is φ = 655277056.

The previous prime is 1639243973. The next prime is 1639243997. The reversal of 1639243990 is 993429361.

It is a super-2 number, since 2×1639243990² = 5374241717502240200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1639243990.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1639243997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35947 + ... + 67606.

It is an arithmetic number, because the mean of its divisors is an integer number (184533228).

Almost surely, 2^1639243990 is an apocalyptic number.

1639243990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1639243990 is a deficient number, since it is larger than the sum of its proper divisors (1313287658).

1639243990 is a wasteful number, since it uses less digits than its factorization.

1639243990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105143.

The product of its (nonzero) digits is 314928, while the sum is 46.

The square root of 1639243990 is about 40487.5782185104. The cubic root of 1639243990 is about 1179.0924722733.

The spelling of 1639243990 in words is "one billion, six hundred thirty-nine million, two hundred forty-three thousand, nine hundred ninety".