20649615 has 16 divisors (see below), whose sum is σ = 37759488. Its totient is φ = 9439776.

The previous prime is 20649613. The next prime is 20649631. The reversal of 20649615 is 51694602.

It is not a de Polignac number, because 20649615 - 2¹ = 20649613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20649613) 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, 98227 + ... + 98436.

It is an arithmetic number, because the mean of its divisors is an integer number (2359968).

Almost surely, 2^20649615 is an apocalyptic number.

20649615 is a deficient number, since it is larger than the sum of its proper divisors (17109873).

20649615 is a wasteful number, since it uses less digits than its factorization.

20649615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196678.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 20649615 is about 4544.1847453641. The cubic root of 20649615 is about 274.3493820378.

The spelling of 20649615 in words is "twenty million, six hundred forty-nine thousand, six hundred fifteen".