18400037281 has 8 divisors (see below), whose sum is σ = 18545114880. Its totient is φ = 18255405072.

The previous prime is 18400037251. The next prime is 18400037309. The reversal of 18400037281 is 18273000481.

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 not a de Polignac number, because 18400037281 - 2²¹ = 18397940129 is a prime.

It is a super-2 number, since 2×18400037281² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18400037231) 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, 28155 + ... + 193888.

It is an arithmetic number, because the mean of its divisors is an integer number (2318139360).

Almost surely, 2^18400037281 is an apocalyptic number.

It is an amenable number.

18400037281 is a deficient number, since it is larger than the sum of its proper divisors (145077599).

18400037281 is a wasteful number, since it uses less digits than its factorization.

18400037281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222695.

The product of its (nonzero) digits is 10752, while the sum is 34.

The spelling of 18400037281 in words is "eighteen billion, four hundred million, thirty-seven thousand, two hundred eighty-one".