21155516040164 has 12 divisors (see below), whose sum is σ = 40387803349488. Its totient is φ = 9616143654600.

The previous prime is 21155516040157. The next prime is 21155516040257. The reversal of 21155516040164 is 46104061555112.

It is a super-2 number, since 2×21155516040164² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 240403591322 + ... + 240403591409.

It is an arithmetic number, because the mean of its divisors is an integer number (3365650279124).

Almost surely, 2^{21155516040164} is an apocalyptic number.

It is an amenable number.

21155516040164 is a deficient number, since it is larger than the sum of its proper divisors (19232287309324).

21155516040164 is a wasteful number, since it uses less digits than its factorization.

21155516040164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480807182746 (or 480807182744 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 41.

Adding to 21155516040164 its reverse (46104061555112), we get a palindrome (67259577595276).

The spelling of 21155516040164 in words is "twenty-one trillion, one hundred fifty-five billion, five hundred sixteen million, forty thousand, one hundred sixty-four".