18951940849 has 4 divisors (see below), whose sum is σ = 19949411440. Its totient is φ = 17954470260.

The previous prime is 18951940841. The next prime is 18951940877. The reversal of 18951940849 is 94804915981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 94804915981 = 1049 ⋅90376469.

It is a cyclic number.

It is not a de Polignac number, because 18951940849 - 2³ = 18951940841 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18951940793 and 18951940802.

It is not an unprimeable number, because it can be changed into a prime (18951940841) 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, 498735267 + ... + 498735304.

It is an arithmetic number, because the mean of its divisors is an integer number (4987352860).

Almost surely, 2^18951940849 is an apocalyptic number.

18951940849 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18951940849 is a deficient number, since it is larger than the sum of its proper divisors (997470591).

18951940849 is an equidigital number, since it uses as much as digits as its factorization.

18951940849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997470590.

The product of its (nonzero) digits is 3732480, while the sum is 58.

The spelling of 18951940849 in words is "eighteen billion, nine hundred fifty-one million, nine hundred forty thousand, eight hundred forty-nine".