215630740 has 24 divisors (see below), whose sum is σ = 487657800. Its totient is φ = 79617408.

The previous prime is 215630717. The next prime is 215630743. The reversal of 215630740 is 47036512.

It can be written as a sum of positive squares in 4 ways, for example, as 19518724 + 196112016 = 4418^2 + 14004^2 .

It is a junction number, because it is equal to n+sod(n) for n = 215630699 and 215630708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215630743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 414415 + ... + 414934.

It is an arithmetic number, because the mean of its divisors is an integer number (20319075).

Almost surely, 2^215630740 is an apocalyptic number.

215630740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215630740 is an abundant number, since it is smaller than the sum of its proper divisors (272027060).

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

215630740 is a wasteful number, since it uses less digits than its factorization.

215630740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 829371 (or 829369 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 215630740 is about 14684.3706027872. The cubic root of 215630740 is about 599.6578975729.

It can be divided in two parts, 2156 and 30740, that added together give a triangular number (32896 = T₂₅₆).

The spelling of 215630740 in words is "two hundred fifteen million, six hundred thirty thousand, seven hundred forty".