212661251 has 6 divisors (see below), whose sum is σ = 233751756. Its totient is φ = 193328300.

The previous prime is 212661227. The next prime is 212661331. The reversal of 212661251 is 152166212.

It is not a de Polignac number, because 212661251 - 2¹⁸ = 212399107 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212661251.

It is not an unprimeable number, because it can be changed into a prime (212661221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 878645 + ... + 878886.

It is an arithmetic number, because the mean of its divisors is an integer number (38958626).

Almost surely, 2^212661251 is an apocalyptic number.

212661251 is a deficient number, since it is larger than the sum of its proper divisors (21090505).

212661251 is a wasteful number, since it uses less digits than its factorization.

212661251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1757553 (or 1757542 counting only the distinct ones).

The product of its digits is 1440, while the sum is 26.

The square root of 212661251 is about 14582.9095519378. The cubic root of 212661251 is about 596.8924992576.

The spelling of 212661251 in words is "two hundred twelve million, six hundred sixty-one thousand, two hundred fifty-one".