215820077 has 12 divisors (see below), whose sum is σ = 238442400. Its totient is φ = 195192360.

The previous prime is 215820071. The next prime is 215820097. The reversal of 215820077 is 770028512.

It is not a de Polignac number, because 215820077 - 2¹⁶ = 215754541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215820071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19598 + ... + 28560.

It is an arithmetic number, because the mean of its divisors is an integer number (19870200).

Almost surely, 2^215820077 is an apocalyptic number.

It is an amenable number.

215820077 is a deficient number, since it is larger than the sum of its proper divisors (22622323).

215820077 is a wasteful number, since it uses less digits than its factorization.

215820077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9184 (or 9173 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 215820077 is about 14690.8160767195. The cubic root of 215820077 is about 599.8333583515.

Adding to 215820077 its reverse (770028512), we get a palindrome (985848589).

The spelling of 215820077 in words is "two hundred fifteen million, eight hundred twenty thousand, seventy-seven".