18940859437 has 4 divisors (see below), whose sum is σ = 18942117436. Its totient is φ = 18939601440.

The previous prime is 18940859411. The next prime is 18940859449. The reversal of 18940859437 is 73495804981.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11520587556 + 7420271881 = 107334^2 + 86141^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18940859437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18940859737) 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 in 3 ways as a sum of consecutive naturals, for example, 606138 + ... + 636619.

It is an arithmetic number, because the mean of its divisors is an integer number (4735529359).

Almost surely, 2^18940859437 is an apocalyptic number.

It is an amenable number.

18940859437 is a deficient number, since it is larger than the sum of its proper divisors (1257999).

18940859437 is a wasteful number, since it uses less digits than its factorization.

18940859437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1257998.

The product of its (nonzero) digits is 8709120, while the sum is 58.

The spelling of 18940859437 in words is "eighteen billion, nine hundred forty million, eight hundred fifty-nine thousand, four hundred thirty-seven".