21557432911 has 8 divisors (see below), whose sum is σ = 24638004000. Its totient is φ = 18477096288.

The previous prime is 21557432909. The next prime is 21557432957. The reversal of 21557432911 is 11923475512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21557432911 - 2¹ = 21557432909 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 (21557432971) 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, 239505 + ... + 316981.

It is an arithmetic number, because the mean of its divisors is an integer number (3079750500).

Almost surely, 2^21557432911 is an apocalyptic number.

21557432911 is a deficient number, since it is larger than the sum of its proper divisors (3080571089).

21557432911 is an equidigital number, since it uses as much as digits as its factorization.

21557432911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117233.

The product of its digits is 75600, while the sum is 40.

The spelling of 21557432911 in words is "twenty-one billion, five hundred fifty-seven million, four hundred thirty-two thousand, nine hundred eleven".