21268723719 has 16 divisors (see below), whose sum is σ = 29459130624. Its totient is φ = 13638475200.

The previous prime is 21268723717. The next prime is 21268723757. The reversal of 21268723719 is 91732786212.

It is a happy number.

It is not a de Polignac number, because 21268723719 - 2¹ = 21268723717 is a prime.

It is a super-2 number, since 2×21268723719² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21268723717) 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, 1208989 + ... + 1226454.

It is an arithmetic number, because the mean of its divisors is an integer number (1841195664).

Almost surely, 2^21268723719 is an apocalyptic number.

21268723719 is a deficient number, since it is larger than the sum of its proper divisors (8190406905).

21268723719 is a wasteful number, since it uses less digits than its factorization.

21268723719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2435558.

The product of its digits is 508032, while the sum is 48.

The spelling of 21268723719 in words is "twenty-one billion, two hundred sixty-eight million, seven hundred twenty-three thousand, seven hundred nineteen".