18879037221781 has 8 divisors (see below), whose sum is σ = 20600644809024. Its totient is φ = 17158318213920.

The previous prime is 18879037221763. The next prime is 18879037221787. The reversal of 18879037221781 is 18712273097881.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18879037221781 is a prime.

It is a super-2 number, since 2×18879037221781² (a number of 27 digits) contains 22 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 (18879037221787) 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, 222100416 + ... + 222185401.

It is an arithmetic number, because the mean of its divisors is an integer number (2575080601128).

Almost surely, 2^{18879037221781} is an apocalyptic number.

18879037221781 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18879037221781 is a deficient number, since it is larger than the sum of its proper divisors (1721607587243).

18879037221781 is a wasteful number, since it uses less digits than its factorization.

18879037221781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444289691.

The product of its (nonzero) digits is 18966528, while the sum is 64.

The spelling of 18879037221781 in words is "eighteen trillion, eight hundred seventy-nine billion, thirty-seven million, two hundred twenty-one thousand, seven hundred eighty-one".