20697787 has 4 divisors (see below), whose sum is σ = 22579416. Its totient is φ = 18816160.

The previous prime is 20697779. The next prime is 20697797. The reversal of 20697787 is 78779602.

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

It is not a de Polignac number, because 20697787 - 2³ = 20697779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20697737) 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, 940798 + ... + 940819.

It is an arithmetic number, because the mean of its divisors is an integer number (5644854).

Almost surely, 2^20697787 is an apocalyptic number.

20697787 is a deficient number, since it is larger than the sum of its proper divisors (1881629).

20697787 is a wasteful number, since it uses less digits than its factorization.

20697787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1881628.

The product of its (nonzero) digits is 296352, while the sum is 46.

The square root of 20697787 is about 4549.4820584326. The cubic root of 20697787 is about 274.5625529997.

The spelling of 20697787 in words is "twenty million, six hundred ninety-seven thousand, seven hundred eighty-seven".