211389961 has 16 divisors (see below), whose sum is σ = 228533760. Its totient is φ = 195068160.

The previous prime is 211389947. The next prime is 211389967. The reversal of 211389961 is 169983112.

It is a cyclic number.

It is not a de Polignac number, because 211389961 - 2⁵ = 211389929 is a prime.

It is a super-2 number, since 2×211389961² = 89371431223163042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211389967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73201 + ... + 76033.

It is an arithmetic number, because the mean of its divisors is an integer number (14283360).

Almost surely, 2^211389961 is an apocalyptic number.

It is an amenable number.

211389961 is a deficient number, since it is larger than the sum of its proper divisors (17143799).

211389961 is a wasteful number, since it uses less digits than its factorization.

211389961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2976.

The product of its digits is 23328, while the sum is 40.

The square root of 211389961 is about 14539.2558612881. The cubic root of 211389961 is about 595.7007124963.

The spelling of 211389961 in words is "two hundred eleven million, three hundred eighty-nine thousand, nine hundred sixty-one".