18937027649 has 4 divisors (see below), whose sum is σ = 18950244036. Its totient is φ = 18923811264.

The previous prime is 18937027619. The next prime is 18937027661. The reversal of 18937027649 is 94672073981.

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 5573667649 + 13363360000 = 74657^2 + 115600^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18937027649 is a prime.

It is a super-2 number, since 2×18937027649² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18937027594 and 18937027603.

It is not an unprimeable number, because it can be changed into a prime (18937027619) 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, 6606044 + ... + 6608909.

It is an arithmetic number, because the mean of its divisors is an integer number (4737561009).

Almost surely, 2^18937027649 is an apocalyptic number.

It is an amenable number.

18937027649 is a deficient number, since it is larger than the sum of its proper divisors (13216387).

18937027649 is a wasteful number, since it uses less digits than its factorization.

18937027649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13216386.

The product of its (nonzero) digits is 4572288, while the sum is 56.

The spelling of 18937027649 in words is "eighteen billion, nine hundred thirty-seven million, twenty-seven thousand, six hundred forty-nine".