215961497 has 2 divisors, whose sum is σ = 215961498. Its totient is φ = 215961496.

The previous prime is 215961433. The next prime is 215961503. The reversal of 215961497 is 794169512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 192959881 + 23001616 = 13891^2 + 4796^2 .

It is a cyclic number.

It is not a de Polignac number, because 215961497 - 2⁶ = 215961433 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (215961397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107980748 + 107980749.

It is an arithmetic number, because the mean of its divisors is an integer number (107980749).

Almost surely, 2^215961497 is an apocalyptic number.

It is an amenable number.

215961497 is a deficient number, since it is larger than the sum of its proper divisors (1).

215961497 is an equidigital number, since it uses as much as digits as its factorization.

215961497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 44.

The square root of 215961497 is about 14695.6284996593. The cubic root of 215961497 is about 599.9643469556.

The spelling of 215961497 in words is "two hundred fifteen million, nine hundred sixty-one thousand, four hundred ninety-seven".