212315551 has 4 divisors (see below), whose sum is σ = 242646352. Its totient is φ = 181984752.

The previous prime is 212315539. The next prime is 212315569. The reversal of 212315551 is 155513212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 212315551 - 2⁹ = 212315039 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 (212315531) 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, 15165390 + ... + 15165403.

It is an arithmetic number, because the mean of its divisors is an integer number (60661588).

Almost surely, 2^212315551 is an apocalyptic number.

212315551 is a deficient number, since it is larger than the sum of its proper divisors (30330801).

212315551 is an equidigital number, since it uses as much as digits as its factorization.

212315551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30330800.

The product of its digits is 1500, while the sum is 25.

The square root of 212315551 is about 14571.0518151573. The cubic root of 212315551 is about 596.5688896856.

Adding to 212315551 its reverse (155513212), we get a palindrome (367828763).

The spelling of 212315551 in words is "two hundred twelve million, three hundred fifteen thousand, five hundred fifty-one".