213154981 has 4 divisors (see below), whose sum is σ = 229551532. Its totient is φ = 196758432.

The previous prime is 213154957. The next prime is 213155003. The reversal of 213154981 is 189451312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 111830625 + 101324356 = 10575^2 + 10066^2 .

It is not a de Polignac number, because 213154981 - 2¹³ = 213146789 is a prime.

It is a super-2 number, since 2×213154981² = 90870091850220722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213155981) 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, 8198256 + ... + 8198281.

It is an arithmetic number, because the mean of its divisors is an integer number (57387883).

Almost surely, 2^213154981 is an apocalyptic number.

It is an amenable number.

213154981 is a deficient number, since it is larger than the sum of its proper divisors (16396551).

213154981 is a wasteful number, since it uses less digits than its factorization.

213154981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16396550.

The product of its digits is 8640, while the sum is 34.

The square root of 213154981 is about 14599.8281154266. The cubic root of 213154981 is about 597.3540720757.

The spelling of 213154981 in words is "two hundred thirteen million, one hundred fifty-four thousand, nine hundred eighty-one".