15645980 has 96 divisors (see below), whose sum is σ = 40449024. Its totient is φ = 4967424.

The previous prime is 15645953. The next prime is 15645983. The reversal of 15645980 is 8954651.

15645980 = T₁₆₀ + T₁₆₁ + ... + T₄₆₀.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15645983) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 138404 + ... + 138516.

It is an arithmetic number, because the mean of its divisors is an integer number (421344).

Almost surely, 2^15645980 is an apocalyptic number.

15645980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a pronic number, being equal to 3955×3956.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15645980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20224512).

15645980 is an abundant number, since it is smaller than the sum of its proper divisors (24803044).

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

15645980 is a wasteful number, since it uses less digits than its factorization.

15645980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 38.

The square root of 15645980 is about 3955.4999683984. The cubic root of 15645980 is about 250.1118432902. Note that the first 3 decimals are identical.

The spelling of 15645980 in words is "fifteen million, six hundred forty-five thousand, nine hundred eighty".