1549997790 has 64 divisors (see below), whose sum is σ = 4074561792. Its totient is φ = 374240000.

The previous prime is 1549997753. The next prime is 1549997809. The reversal of 1549997790 is 977999451.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 73474 + ... + 92186.

It is an arithmetic number, because the mean of its divisors is an integer number (63665028).

Almost surely, 2^1549997790 is an apocalyptic number.

1549997790 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 1549997790, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2037280896).

1549997790 is an abundant number, since it is smaller than the sum of its proper divisors (2524564002).

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

1549997790 is a wasteful number, since it uses less digits than its factorization.

1549997790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18985.

The product of its (nonzero) digits is 6429780, while the sum is 60.

The square root of 1549997790 is about 39370.0113030210. The cubic root of 1549997790 is about 1157.2939772367.

The spelling of 1549997790 in words is "one billion, five hundred forty-nine million, nine hundred ninety-seven thousand, seven hundred ninety".