20617907 has 4 divisors (see below), whose sum is σ = 21703080. Its totient is φ = 19532736.

The previous prime is 20617879. The next prime is 20617921. The reversal of 20617907 is 70971602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20617907 - 2¹² = 20613811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20617007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 542558 + ... + 542595.

It is an arithmetic number, because the mean of its divisors is an integer number (5425770).

Almost surely, 2^20617907 is an apocalyptic number.

20617907 is a deficient number, since it is larger than the sum of its proper divisors (1085173).

20617907 is a wasteful number, since it uses less digits than its factorization.

20617907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1085172.

The product of its (nonzero) digits is 5292, while the sum is 32.

The square root of 20617907 is about 4540.6945503964. The cubic root of 20617907 is about 274.2088866572.

The spelling of 20617907 in words is "twenty million, six hundred seventeen thousand, nine hundred seven".