213115551 has 16 divisors (see below), whose sum is σ = 310746240. Its totient is φ = 128844320.

The previous prime is 213115537. The next prime is 213115561. The reversal of 213115551 is 155511312.

It is not a de Polignac number, because 213115551 - 2⁷ = 213115423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213115501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6121 + ... + 21533.

It is an arithmetic number, because the mean of its divisors is an integer number (19421640).

Almost surely, 2^213115551 is an apocalyptic number.

213115551 is a deficient number, since it is larger than the sum of its proper divisors (97630689).

213115551 is a wasteful number, since it uses less digits than its factorization.

213115551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15846.

The product of its digits is 750, while the sum is 24.

The square root of 213115551 is about 14598.4776946091. The cubic root of 213115551 is about 597.3172363995.

Adding to 213115551 its reverse (155511312), we get a palindrome (368626863).

It can be divided in two parts, 21311 and 5551, that added together give a palindrome (26862).

The spelling of 213115551 in words is "two hundred thirteen million, one hundred fifteen thousand, five hundred fifty-one".