210055981 has 8 divisors (see below), whose sum is σ = 211894560. Its totient is φ = 208224432.

The previous prime is 210055973. The next prime is 210055991. The reversal of 210055981 is 189550012.

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 210055981 - 2³ = 210055973 is a prime.

It is a super-2 number, since 2×210055981² = 88247030307744722, 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 (210055991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70755 + ... + 73663.

It is an arithmetic number, because the mean of its divisors is an integer number (26486820).

Almost surely, 2^210055981 is an apocalyptic number.

It is an amenable number.

210055981 is a deficient number, since it is larger than the sum of its proper divisors (1838579).

210055981 is a wasteful number, since it uses less digits than its factorization.

210055981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3515.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 210055981 is about 14493.3081454856. The cubic root of 210055981 is about 594.4450075195.

It can be divided in two parts, 2100 and 55981, that added together give a square (58081 = 241²).

The spelling of 210055981 in words is "two hundred ten million, fifty-five thousand, nine hundred eighty-one".