7218501890 has 32 divisors (see below), whose sum is σ = 13074534000. Its totient is φ = 2869401600.

The previous prime is 7218501881. The next prime is 7218501923. The reversal of 7218501890 is 981058127.

It can be written as a sum of positive squares in 8 ways, for example, as 1141831681 + 6076670209 = 33791^2 + 77953^2 .

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1252736 + ... + 1258484.

Almost surely, 2^7218501890 is an apocalyptic number.

7218501890 is a deficient number, since it is larger than the sum of its proper divisors (5856032110).

7218501890 is a wasteful number, since it uses less digits than its factorization.

7218501890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6518.

The product of its (nonzero) digits is 40320, while the sum is 41.

The square root of 7218501890 is about 84961.7672250289. The cubic root of 7218501890 is about 1932.6313709688.

The spelling of 7218501890 in words is "seven billion, two hundred eighteen million, five hundred one thousand, eight hundred ninety".