215240551 has 2 divisors, whose sum is σ = 215240552. Its totient is φ = 215240550.

The previous prime is 215240449. The next prime is 215240561. The reversal of 215240551 is 155042512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215240551 - 2⁷ = 215240423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215240561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107620275 + 107620276.

It is an arithmetic number, because the mean of its divisors is an integer number (107620276).

Almost surely, 2^215240551 is an apocalyptic number.

215240551 is a deficient number, since it is larger than the sum of its proper divisors (1).

215240551 is an equidigital number, since it uses as much as digits as its factorization.

215240551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 215240551 is about 14671.0787265286. The cubic root of 215240551 is about 599.2959807327.

The spelling of 215240551 in words is "two hundred fifteen million, two hundred forty thousand, five hundred fifty-one".