213756649 has 4 divisors (see below), whose sum is σ = 213967440. Its totient is φ = 213545860.

The previous prime is 213756617. The next prime is 213756661. The reversal of 213756649 is 946657312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 213756649 - 2⁵ = 213756617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213756349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103867 + ... + 105904.

It is an arithmetic number, because the mean of its divisors is an integer number (53491860).

Almost surely, 2^213756649 is an apocalyptic number.

It is an amenable number.

213756649 is a deficient number, since it is larger than the sum of its proper divisors (210791).

213756649 is a wasteful number, since it uses less digits than its factorization.

213756649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210790.

The product of its digits is 272160, while the sum is 43.

The square root of 213756649 is about 14620.4189064472. The cubic root of 213756649 is about 597.9155902603.

The spelling of 213756649 in words is "two hundred thirteen million, seven hundred fifty-six thousand, six hundred forty-nine".