215428780 has 24 divisors (see below), whose sum is σ = 517029408. Its totient is φ = 73861248.

The previous prime is 215428757. The next prime is 215428781. The reversal of 215428780 is 87824512.

It is not an unprimeable number, because it can be changed into a prime (215428781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 769249 + ... + 769528.

It is an arithmetic number, because the mean of its divisors is an integer number (21542892).

Almost surely, 2^215428780 is an apocalyptic number.

215428780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215428780 is an abundant number, since it is smaller than the sum of its proper divisors (301600628).

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

215428780 is a wasteful number, since it uses less digits than its factorization.

215428780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1538793 (or 1538791 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 37.

The square root of 215428780 is about 14677.4922926227. The cubic root of 215428780 is about 599.4706256680.

The spelling of 215428780 in words is "two hundred fifteen million, four hundred twenty-eight thousand, seven hundred eighty".