215450021051 has 4 divisors (see below), whose sum is σ = 216142786704. Its totient is φ = 214757255400.

The previous prime is 215450021041. The next prime is 215450021071. The reversal of 215450021051 is 150120054512.

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

It is a cyclic number.

It is not a de Polignac number, because 215450021051 - 2¹⁸ = 215449758907 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 215450021051.

It is not an unprimeable number, because it can be changed into a prime (215450021011) 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, 346382360 + ... + 346382981.

It is an arithmetic number, because the mean of its divisors is an integer number (54035696676).

Almost surely, 2^215450021051 is an apocalyptic number.

215450021051 is a deficient number, since it is larger than the sum of its proper divisors (692765653).

215450021051 is an equidigital number, since it uses as much as digits as its factorization.

215450021051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692765652.

The product of its (nonzero) digits is 2000, while the sum is 26.

Adding to 215450021051 its reverse (150120054512), we get a palindrome (365570075563).

The spelling of 215450021051 in words is "two hundred fifteen billion, four hundred fifty million, twenty-one thousand, fifty-one".