21771703755 has 24 divisors (see below), whose sum is σ = 39723811920. Its totient is φ = 11000439360.

The previous prime is 21771703753. The next prime is 21771703757. The reversal of 21771703755 is 55730717712.

It is an interprime number because it is at equal distance from previous prime (21771703753) and next prime (21771703757).

It is not a de Polignac number, because 21771703755 - 2¹ = 21771703753 is a prime.

It is a super-2 number, since 2×21771703755² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21771703755.

It is not an unprimeable number, because it can be changed into a prime (21771703753) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12731136 + ... + 12732845.

It is an arithmetic number, because the mean of its divisors is an integer number (1655158830).

Almost surely, 2^21771703755 is an apocalyptic number.

21771703755 is a deficient number, since it is larger than the sum of its proper divisors (17952108165).

21771703755 is a wasteful number, since it uses less digits than its factorization.

21771703755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25464011 (or 25464008 counting only the distinct ones).

The product of its (nonzero) digits is 360150, while the sum is 45.

The spelling of 21771703755 in words is "twenty-one billion, seven hundred seventy-one million, seven hundred three thousand, seven hundred fifty-five".