1538681780 has 24 divisors (see below), whose sum is σ = 3233274408. Its totient is φ = 615083648.

The previous prime is 1538681777. The next prime is 1538681821. The reversal of 1538681780 is 871868351.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2704 + 1538679076 = 52^2 + 39226^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9242 + ... + 56238.

It is an arithmetic number, because the mean of its divisors is an integer number (134719767).

Almost surely, 2^1538681780 is an apocalyptic number.

1538681780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1538681780 is an abundant number, since it is smaller than the sum of its proper divisors (1694592628).

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

1538681780 is a wasteful number, since it uses less digits than its factorization.

1538681780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48643 (or 48641 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 47.

The square root of 1538681780 is about 39226.0344669201. The cubic root of 1538681780 is about 1154.4707581973.

The spelling of 1538681780 in words is "one billion, five hundred thirty-eight million, six hundred eighty-one thousand, seven hundred eighty".