21719065 has 8 divisors (see below), whose sum is σ = 26903808. Its totient is φ = 16814640.

The previous prime is 21719063. The next prime is 21719069. The reversal of 21719065 is 56091712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21719065 - 2¹ = 21719063 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21719063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69907 + ... + 70216.

It is an arithmetic number, because the mean of its divisors is an integer number (3362976).

Almost surely, 2^21719065 is an apocalyptic number.

It is an amenable number.

21719065 is a deficient number, since it is larger than the sum of its proper divisors (5184743).

21719065 is a wasteful number, since it uses less digits than its factorization.

21719065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140159.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 21719065 is about 4660.3717662865. The cubic root of 21719065 is about 279.0061063312.

It can be divided in two parts, 2171 and 9065, that added together give a square (11236 = 106²).

The spelling of 21719065 in words is "twenty-one million, seven hundred nineteen thousand, sixty-five".