213778281 has 16 divisors (see below), whose sum is σ = 303174144. Its totient is φ = 133526784.

The previous prime is 213778277. The next prime is 213778289. The reversal of 213778281 is 182877312.

It is not a de Polignac number, because 213778281 - 2² = 213778277 is a prime.

It is a super-2 number, since 2×213778281² = 91402306854629922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (213778289) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1975 + ... + 20771.

It is an arithmetic number, because the mean of its divisors is an integer number (18948384).

Almost surely, 2^213778281 is an apocalyptic number.

It is an amenable number.

213778281 is a deficient number, since it is larger than the sum of its proper divisors (89395863).

213778281 is a wasteful number, since it uses less digits than its factorization.

213778281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19040.

The product of its digits is 37632, while the sum is 39.

The square root of 213778281 is about 14621.1586750161. The cubic root of 213778281 is about 597.9357591047.

The spelling of 213778281 in words is "two hundred thirteen million, seven hundred seventy-eight thousand, two hundred eighty-one".