213105981 has 8 divisors (see below), whose sum is σ = 309972384. Its totient is φ = 129155120.

The previous prime is 213105973. The next prime is 213105989. The reversal of 213105981 is 189501312.

It is an interprime number because it is at equal distance from previous prime (213105973) and next prime (213105989).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 213105981 - 2³ = 213105973 is a prime.

It is a super-2 number, since 2×213105981² = 90828318275944722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213105989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3228846 + ... + 3228911.

It is an arithmetic number, because the mean of its divisors is an integer number (38746548).

Almost surely, 2^213105981 is an apocalyptic number.

It is an amenable number.

213105981 is a deficient number, since it is larger than the sum of its proper divisors (96866403).

213105981 is a wasteful number, since it uses less digits than its factorization.

213105981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6457771.

The product of its (nonzero) digits is 2160, while the sum is 30.

The square root of 213105981 is about 14598.1499170272. The cubic root of 213105981 is about 597.3082953790.

The spelling of 213105981 in words is "two hundred thirteen million, one hundred five thousand, nine hundred eighty-one".