215640542 has 16 divisors (see below), whose sum is σ = 349408752. Its totient is φ = 99221760.

The previous prime is 215640511. The next prime is 215640553. The reversal of 215640542 is 245046512.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 3923 + ... + 21134.

It is an arithmetic number, because the mean of its divisors is an integer number (21838047).

Almost surely, 2^215640542 is an apocalyptic number.

215640542 is a deficient number, since it is larger than the sum of its proper divisors (133768210).

215640542 is a wasteful number, since it uses less digits than its factorization.

215640542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25403.

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 215640542 is about 14684.7043552126. The cubic root of 215640542 is about 599.6669837196. Note that the first 3 decimals are identical.

The spelling of 215640542 in words is "two hundred fifteen million, six hundred forty thousand, five hundred forty-two".