15780920 has 16 divisors (see below), whose sum is σ = 35507160. Its totient is φ = 6312352.

The previous prime is 15780917. The next prime is 15780937. The reversal of 15780920 is 2908751.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 197222 + ... + 197301.

Almost surely, 2^15780920 is an apocalyptic number.

15780920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15780920 is an abundant number, since it is smaller than the sum of its proper divisors (19726240).

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

15780920 is a wasteful number, since it uses less digits than its factorization.

15780920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394534 (or 394530 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 15780920 is about 3972.5206103934. The cubic root of 15780920 is about 250.8288225098.

The spelling of 15780920 in words is "fifteen million, seven hundred eighty thousand, nine hundred twenty".