21179064849497 has 4 divisors (see below), whose sum is σ = 21179106636816. Its totient is φ = 21179023062180.

The previous prime is 21179064849473. The next prime is 21179064849599. The reversal of 21179064849497 is 79494846097112.

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 21179064849497 - 2⁴² = 16781018338393 is a prime.

It is a super-2 number, since 2×21179064849497² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21179064849497.

It is not an unprimeable number, because it can be changed into a prime (21179064849797) 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, 20123963 + ... + 21150224.

It is an arithmetic number, because the mean of its divisors is an integer number (5294776659204).

Almost surely, 2^{21179064849497} is an apocalyptic number.

It is an amenable number.

21179064849497 is a deficient number, since it is larger than the sum of its proper divisors (41787319).

21179064849497 is an equidigital number, since it uses as much as digits as its factorization.

21179064849497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41787318.

The product of its (nonzero) digits is 219469824, while the sum is 71.

The spelling of 21179064849497 in words is "twenty-one trillion, one hundred seventy-nine billion, sixty-four million, eight hundred forty-nine thousand, four hundred ninety-seven".