21696391758 has 16 divisors (see below), whose sum is σ = 43987206096. Its totient is φ = 7133060160.

The previous prime is 21696391753. The next prime is 21696391877. The reversal of 21696391758 is 85719369612.

It is a super-2 number, since 2×21696391758² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21696391698 and 21696391707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21696391753) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24767133 + ... + 24768008.

It is an arithmetic number, because the mean of its divisors is an integer number (2749200381).

Almost surely, 2^21696391758 is an apocalyptic number.

21696391758 is an abundant number, since it is smaller than the sum of its proper divisors (22290814338).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21696391758 is a wasteful number, since it uses less digits than its factorization.

21696391758 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49535219.

The product of its digits is 4898880, while the sum is 57.

The spelling of 21696391758 in words is "twenty-one billion, six hundred ninety-six million, three hundred ninety-one thousand, seven hundred fifty-eight".