215820542 has 16 divisors (see below), whose sum is σ = 391741920. Its totient is φ = 87053568.

The previous prime is 215820541. The next prime is 215820607. The reversal of 215820542 is 245028512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215820541) by changing a digit.

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, 453167 + ... + 453642.

It is an arithmetic number, because the mean of its divisors is an integer number (24483870).

Almost surely, 2^215820542 is an apocalyptic number.

215820542 is a deficient number, since it is larger than the sum of its proper divisors (175921378).

215820542 is a wasteful number, since it uses less digits than its factorization.

215820542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 906835.

The product of its (nonzero) digits is 6400, while the sum is 29.

The square root of 215820542 is about 14690.8319029250. The cubic root of 215820542 is about 599.8337891460.

The spelling of 215820542 in words is "two hundred fifteen million, eight hundred twenty thousand, five hundred forty-two".