211497921 has 6 divisors (see below), whose sum is σ = 305497010. Its totient is φ = 140998608.

The previous prime is 211497889. The next prime is 211497941. The reversal of 211497921 is 129794112.

211497921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 159138225 + 52359696 = 12615^2 + 7236^2 .

It is not a de Polignac number, because 211497921 - 2⁵ = 211497889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (211497941) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11749876 + ... + 11749893.

Almost surely, 2^211497921 is an apocalyptic number.

It is an amenable number.

211497921 is a deficient number, since it is larger than the sum of its proper divisors (93999089).

211497921 is a wasteful number, since it uses less digits than its factorization.

211497921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23499775 (or 23499772 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 211497921 is about 14542.9680945810. The cubic root of 211497921 is about 595.8021063111.

The spelling of 211497921 in words is "two hundred eleven million, four hundred ninety-seven thousand, nine hundred twenty-one".