21356735755 has 4 divisors (see below), whose sum is σ = 25628082912. Its totient is φ = 17085388600.

The previous prime is 21356735749. The next prime is 21356735761. The reversal of 21356735755 is 55753765312.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21356735749) and next prime (21356735761).

It is not a de Polignac number, because 21356735755 - 2¹³ = 21356727563 is a prime.

It is a super-2 number, since 2×21356735755² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21356735699 and 21356735708.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2135673571 + ... + 2135673580.

It is an arithmetic number, because the mean of its divisors is an integer number (6407020728).

Almost surely, 2^21356735755 is an apocalyptic number.

21356735755 is a deficient number, since it is larger than the sum of its proper divisors (4271347157).

21356735755 is an equidigital number, since it uses as much as digits as its factorization.

21356735755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4271347156.

The product of its digits is 3307500, while the sum is 49.

The spelling of 21356735755 in words is "twenty-one billion, three hundred fifty-six million, seven hundred thirty-five thousand, seven hundred fifty-five".