21156045599 has 4 divisors (see below), whose sum is σ = 22783433736. Its totient is φ = 19528657464.

The previous prime is 21156045571. The next prime is 21156045649. The reversal of 21156045599 is 99554065112.

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 21156045599 - 2¹² = 21156041503 is a prime.

It is a super-3 number, since 3×21156045599³ (a number of 32 digits) contains 333 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 (21156045509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 813694049 + ... + 813694074.

It is an arithmetic number, because the mean of its divisors is an integer number (5695858434).

Almost surely, 2^21156045599 is an apocalyptic number.

21156045599 is a deficient number, since it is larger than the sum of its proper divisors (1627388137).

21156045599 is a wasteful number, since it uses less digits than its factorization.

21156045599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627388136.

The product of its (nonzero) digits is 486000, while the sum is 47.

The spelling of 21156045599 in words is "twenty-one billion, one hundred fifty-six million, forty-five thousand, five hundred ninety-nine".