213566949 has 20 divisors (see below), whose sum is σ = 321869196. Its totient is φ = 141111936.

The previous prime is 213566929. The next prime is 213566957. The reversal of 213566949 is 949665312.

It can be written as a sum of positive squares in 2 ways, for example, as 5688225 + 207878724 = 2385^2 + 14418^2 .

It is not a de Polignac number, because 213566949 - 2⁸ = 213566693 is a prime.

It is a super-2 number, since 2×213566949² = 91221683410337202, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213566929) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2514 + ... + 20819.

Almost surely, 2^213566949 is an apocalyptic number.

It is an amenable number.

213566949 is a deficient number, since it is larger than the sum of its proper divisors (108302247).

213566949 is a wasteful number, since it uses less digits than its factorization.

213566949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23458 (or 23449 counting only the distinct ones).

The product of its digits is 349920, while the sum is 45.

The square root of 213566949 is about 14613.9299642499. The cubic root of 213566949 is about 597.7386629651.

The spelling of 213566949 in words is "two hundred thirteen million, five hundred sixty-six thousand, nine hundred forty-nine".