215488138849 has 9 divisors (see below), whose sum is σ = 218514831123. Its totient is φ = 212502823632.

The previous prime is 215488138843. The next prime is 215488138889. The reversal of 215488138849 is 948831884512.

It is a happy number.

The square root of 215488138849 is 464207.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 122321565025 + 93166573824 = 349745^2 + 305232^2 .

It is not a de Polignac number, because 215488138849 - 2²¹ = 215486041697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (215488138843) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 33883932 + ... + 33890290.

Almost surely, 2^215488138849 is an apocalyptic number.

215488138849 is the 464207-th square number.

215488138849 is the 232104-th centered octagonal number.

It is an amenable number.

215488138849 is a deficient number, since it is larger than the sum of its proper divisors (3026692274).

215488138849 is an frugal number, since it uses more digits than its factorization.

215488138849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12864 (or 6432 counting only the distinct ones).

The product of its digits is 17694720, while the sum is 61.

The spelling of 215488138849 in words is "two hundred fifteen billion, four hundred eighty-eight million, one hundred thirty-eight thousand, eight hundred forty-nine".