66210245 has 4 divisors (see below), whose sum is σ = 79452300. Its totient is φ = 52968192.

The previous prime is 66210191. The next prime is 66210251. The reversal of 66210245 is 54201266.

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 49547521 + 16662724 = 7039^2 + 4082^2 .

It is a cyclic number.

It is not a de Polignac number, because 66210245 - 2⁶ = 66210181 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6621020 + ... + 6621029.

It is an arithmetic number, because the mean of its divisors is an integer number (19863075).

Almost surely, 2^66210245 is an apocalyptic number.

It is an amenable number.

66210245 is a deficient number, since it is larger than the sum of its proper divisors (13242055).

66210245 is a wasteful number, since it uses less digits than its factorization.

66210245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13242054.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 66210245 is about 8136.9678013373. The cubic root of 66210245 is about 404.5526636307.

The spelling of 66210245 in words is "sixty-six million, two hundred ten thousand, two hundred forty-five".