215220100 has 18 divisors (see below), whose sum is σ = 467027834. Its totient is φ = 86088000.

The previous prime is 215220091. The next prime is 215220127. The reversal of 215220100 is 1022512.

It can be written as a sum of positive squares in 3 ways, for example, as 1592644 + 213627456 = 1262^2 + 14616^2 .

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 5 ways as a sum of consecutive naturals, for example, 1076001 + ... + 1076200.

Almost surely, 2^215220100 is an apocalyptic number.

215220100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215220100 is an abundant number, since it is smaller than the sum of its proper divisors (251807734).

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

215220100 is a wasteful number, since it uses less digits than its factorization.

215220100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2152215 (or 2152208 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 215220100 is about 14670.3817264582. The cubic root of 215220100 is about 599.2769995041.

Adding to 215220100 its reverse (1022512), we get a palindrome (216242612).

The spelling of 215220100 in words is "two hundred fifteen million, two hundred twenty thousand, one hundred".