213551121 has 32 divisors (see below), whose sum is σ = 330624000. Its totient is φ = 120093120.

The previous prime is 213551119. The next prime is 213551123. The reversal of 213551121 is 121155312.

It is an interprime number because it is at equal distance from previous prime (213551119) and next prime (213551123).

It is not a de Polignac number, because 213551121 - 2¹ = 213551119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (213551123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 434686 + ... + 435176.

It is an arithmetic number, because the mean of its divisors is an integer number (10332000).

Almost surely, 2^213551121 is an apocalyptic number.

213551121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

213551121 is a deficient number, since it is larger than the sum of its proper divisors (117072879).

213551121 is a wasteful number, since it uses less digits than its factorization.

213551121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 789.

The product of its digits is 300, while the sum is 21.

The square root of 213551121 is about 14613.3884161066. The cubic root of 213551121 is about 597.7238959466.

The spelling of 213551121 in words is "two hundred thirteen million, five hundred fifty-one thousand, one hundred twenty-one".