1549943820 has 72 divisors (see below), whose sum is σ = 4706782080. Its totient is φ = 412853760.

The previous prime is 1549943789. The next prime is 1549943827. The reversal of 1549943820 is 283499451.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1549943827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 174036 + ... + 182724.

Almost surely, 2^1549943820 is an apocalyptic number.

1549943820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1549943820 is an abundant number, since it is smaller than the sum of its proper divisors (3156838260).

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

1549943820 is a wasteful number, since it uses less digits than its factorization.

1549943820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9695 (or 9690 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 1549943820 is about 39369.3258768803. The cubic root of 1549943820 is about 1157.2805449851.

It can be divided in two parts, 15499 and 43820, that added together give a cube (59319 = 39³).

The spelling of 1549943820 in words is "one billion, five hundred forty-nine million, nine hundred forty-three thousand, eight hundred twenty".