20719665 has 32 divisors (see below), whose sum is σ = 38442240. Its totient is φ = 10568448.

The previous prime is 20719639. The next prime is 20719693. The reversal of 20719665 is 56691702.

It is not a de Polignac number, because 20719665 - 2⁷ = 20719537 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 232 + ... + 6441.

It is an arithmetic number, because the mean of its divisors is an integer number (1201320).

Almost surely, 2^20719665 is an apocalyptic number.

It is an amenable number.

20719665 is a deficient number, since it is larger than the sum of its proper divisors (17722575).

20719665 is a wasteful number, since it uses less digits than its factorization.

20719665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6710 (or 6704 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 20719665 is about 4551.8858729103. The cubic root of 20719665 is about 274.6592584158.

The spelling of 20719665 in words is "twenty million, seven hundred nineteen thousand, six hundred sixty-five".