212779381 has 16 divisors (see below), whose sum is σ = 227824128. Its totient is φ = 198374400.

The previous prime is 212779379. The next prime is 212779421. The reversal of 212779381 is 183977212.

It is a happy number.

It is not a de Polignac number, because 212779381 - 2¹ = 212779379 is a prime.

It is a super-2 number, since 2×212779381² = 90550129957486322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212779321) 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, 104485 + ... + 106501.

It is an arithmetic number, because the mean of its divisors is an integer number (14239008).

Almost surely, 2^212779381 is an apocalyptic number.

It is an amenable number.

212779381 is a deficient number, since it is larger than the sum of its proper divisors (15044747).

212779381 is a wasteful number, since it uses less digits than its factorization.

212779381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2172.

The product of its digits is 42336, while the sum is 40.

The square root of 212779381 is about 14586.9592787531. The cubic root of 212779381 is about 597.0030002833.

The spelling of 212779381 in words is "two hundred twelve million, seven hundred seventy-nine thousand, three hundred eighty-one".