21636719701 has 4 divisors (see below), whose sum is σ = 21941462304. Its totient is φ = 21331977100.

The previous prime is 21636719683. The next prime is 21636719761. The reversal of 21636719701 is 10791763612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21636719701 - 2⁹ = 21636719189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21636719761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152371195 + ... + 152371336.

It is an arithmetic number, because the mean of its divisors is an integer number (5485365576).

Almost surely, 2^21636719701 is an apocalyptic number.

It is an amenable number.

21636719701 is a deficient number, since it is larger than the sum of its proper divisors (304742603).

21636719701 is an equidigital number, since it uses as much as digits as its factorization.

21636719701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304742602.

The product of its (nonzero) digits is 95256, while the sum is 43.

The spelling of 21636719701 in words is "twenty-one billion, six hundred thirty-six million, seven hundred nineteen thousand, seven hundred one".