212699681 has 4 divisors (see below), whose sum is σ = 213636912. Its totient is φ = 211762452.

The previous prime is 212699651. The next prime is 212699749. The reversal of 212699681 is 186996212.

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 a de Polignac number, because none of the positive numbers 2^k-212699681 is a prime.

It is a super-2 number, since 2×212699681² = 90482308595003522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (212699651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 468275 + ... + 468728.

It is an arithmetic number, because the mean of its divisors is an integer number (53409228).

Almost surely, 2^212699681 is an apocalyptic number.

It is an amenable number.

212699681 is a deficient number, since it is larger than the sum of its proper divisors (937231).

212699681 is an equidigital number, since it uses as much as digits as its factorization.

212699681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 937230.

The product of its digits is 93312, while the sum is 44.

The square root of 212699681 is about 14584.2271307053. The cubic root of 212699681 is about 596.9284518928.

The spelling of 212699681 in words is "two hundred twelve million, six hundred ninety-nine thousand, six hundred eighty-one".