21166056502 has 4 divisors (see below), whose sum is σ = 31749084756. Its totient is φ = 10583028250.

The previous prime is 21166056479. The next prime is 21166056503. The reversal of 21166056502 is 20565066112.

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

It is a super-3 number, since 3×21166056502³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21166056503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5291514124 + ... + 5291514127.

It is an arithmetic number, because the mean of its divisors is an integer number (7937271189).

Almost surely, 2^21166056502 is an apocalyptic number.

21166056502 is a deficient number, since it is larger than the sum of its proper divisors (10583028254).

21166056502 is a wasteful number, since it uses less digits than its factorization.

21166056502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10583028253.

The product of its (nonzero) digits is 21600, while the sum is 34.

The spelling of 21166056502 in words is "twenty-one billion, one hundred sixty-six million, fifty-six thousand, five hundred two".