20356721311 has 4 divisors (see below), whose sum is σ = 20370449512. Its totient is φ = 20342993112.

The previous prime is 20356721269. The next prime is 20356721321. The reversal of 20356721311 is 11312765302.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20356721311 - 2⁹ = 20356720799 is a prime.

It is a super-2 number, since 2×20356721311² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20356721321) 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, 6861876 + ... + 6864841.

It is an arithmetic number, because the mean of its divisors is an integer number (5092612378).

Almost surely, 2^20356721311 is an apocalyptic number.

20356721311 is a deficient number, since it is larger than the sum of its proper divisors (13728201).

20356721311 is a wasteful number, since it uses less digits than its factorization.

20356721311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13728200.

The product of its (nonzero) digits is 7560, while the sum is 31.

The spelling of 20356721311 in words is "twenty billion, three hundred fifty-six million, seven hundred twenty-one thousand, three hundred eleven".