215738649 has 12 divisors (see below), whose sum is σ = 356140096. Its totient is φ = 123279192.

The previous prime is 215738647. The next prime is 215738657. The reversal of 215738649 is 946837512.

It is not a de Polignac number, because 215738649 - 2¹ = 215738647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215738647) 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, 1712149 + ... + 1712274.

Almost surely, 2^215738649 is an apocalyptic number.

It is an amenable number.

215738649 is a deficient number, since it is larger than the sum of its proper divisors (140401447).

215738649 is a wasteful number, since it uses less digits than its factorization.

215738649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3424436 (or 3424433 counting only the distinct ones).

The product of its digits is 362880, while the sum is 45.

The square root of 215738649 is about 14688.0444239524. The cubic root of 215738649 is about 599.7579106677.

The spelling of 215738649 in words is "two hundred fifteen million, seven hundred thirty-eight thousand, six hundred forty-nine".