215555520137 has 2 divisors, whose sum is σ = 215555520138. Its totient is φ = 215555520136.

The previous prime is 215555520091. The next prime is 215555520221. The reversal of 215555520137 is 731025555512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141604700416 + 73950819721 = 376304^2 + 271939^2 .

It is a cyclic number.

It is not a de Polignac number, because 215555520137 - 2¹⁴ = 215555503753 is a prime.

It is a super-2 number, since 2×215555520137² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 215555520094 and 215555520103.

It is not a weakly prime, because it can be changed into another prime (215555520637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107777760068 + 107777760069.

It is an arithmetic number, because the mean of its divisors is an integer number (107777760069).

Almost surely, 2^215555520137 is an apocalyptic number.

It is an amenable number.

215555520137 is a deficient number, since it is larger than the sum of its proper divisors (1).

215555520137 is an equidigital number, since it uses as much as digits as its factorization.

215555520137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 262500, while the sum is 41.

The spelling of 215555520137 in words is "two hundred fifteen billion, five hundred fifty-five million, five hundred twenty thousand, one hundred thirty-seven".