212253661 has 4 divisors (see below), whose sum is σ = 212284800. Its totient is φ = 212222524.

The previous prime is 212253649. The next prime is 212253673. The reversal of 212253661 is 166352212.

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, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (212253649) and next prime (212253673).

It is a cyclic number.

It is not a de Polignac number, because 212253661 - 2²¹ = 210156509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212253061) 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, 451 + ... + 20608.

It is an arithmetic number, because the mean of its divisors is an integer number (53071200).

Almost surely, 2^212253661 is an apocalyptic number.

It is an amenable number.

212253661 is a deficient number, since it is larger than the sum of its proper divisors (31139).

212253661 is a wasteful number, since it uses less digits than its factorization.

212253661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31138.

The product of its digits is 4320, while the sum is 28.

The square root of 212253661 is about 14568.9279289864. The cubic root of 212253661 is about 596.5109174260.

The spelling of 212253661 in words is "two hundred twelve million, two hundred fifty-three thousand, six hundred sixty-one".