215421051 has 4 divisors (see below), whose sum is σ = 287228072. Its totient is φ = 143614032.

The previous prime is 215421043. The next prime is 215421119. The reversal of 215421051 is 150124512.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 215421051 - 2³ = 215421043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215423051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35903506 + ... + 35903511.

It is an arithmetic number, because the mean of its divisors is an integer number (71807018).

Almost surely, 2^215421051 is an apocalyptic number.

215421051 is a deficient number, since it is larger than the sum of its proper divisors (71807021).

215421051 is an equidigital number, since it uses as much as digits as its factorization.

215421051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71807020.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 215421051 is about 14677.2289959651. The cubic root of 215421051 is about 599.4634564558.

Adding to 215421051 its reverse (150124512), we get a palindrome (365545563).

The spelling of 215421051 in words is "two hundred fifteen million, four hundred twenty-one thousand, fifty-one".