212991747 has 8 divisors (see below), whose sum is σ = 293781840. Its totient is φ = 137098080.

The previous prime is 212991697. The next prime is 212991749. The reversal of 212991747 is 747199212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 212991747 - 2⁷ = 212991619 is a prime.

It is a super-2 number, since 2×212991747² = 90730968580224018, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 212991699 and 212991708.

It is not an unprimeable number, because it can be changed into a prime (212991749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1224004 + ... + 1224177.

It is an arithmetic number, because the mean of its divisors is an integer number (36722730).

Almost surely, 2^212991747 is an apocalyptic number.

212991747 is a deficient number, since it is larger than the sum of its proper divisors (80790093).

212991747 is a wasteful number, since it uses less digits than its factorization.

212991747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2448213.

The product of its digits is 63504, while the sum is 42.

The square root of 212991747 is about 14594.2367734664. The cubic root of 212991747 is about 597.2015486310.

The spelling of 212991747 in words is "two hundred twelve million, nine hundred ninety-one thousand, seven hundred forty-seven".