20715945 has 16 divisors (see below), whose sum is σ = 35095680. Its totient is φ = 10398464.

The previous prime is 20715941. The next prime is 20715973. The reversal of 20715945 is 54951702.

It is a cyclic number.

It is not a de Polignac number, because 20715945 - 2² = 20715941 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20715941) 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, 40365 + ... + 40874.

It is an arithmetic number, because the mean of its divisors is an integer number (2193480).

Almost surely, 2^20715945 is an apocalyptic number.

It is an amenable number.

20715945 is a deficient number, since it is larger than the sum of its proper divisors (14379735).

20715945 is a wasteful number, since it uses less digits than its factorization.

20715945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81264.

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 20715945 is about 4551.4772327235. The cubic root of 20715945 is about 274.6428200291.

The spelling of 20715945 in words is "twenty million, seven hundred fifteen thousand, nine hundred forty-five".