18951323749 has 2 divisors, whose sum is σ = 18951323750. Its totient is φ = 18951323748.

The previous prime is 18951323719. The next prime is 18951323753. The reversal of 18951323749 is 94732315981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14833534849 + 4117788900 = 121793^2 + 64170^2 .

It is a cyclic number.

It is not a de Polignac number, because 18951323749 - 2⁵ = 18951323717 is a prime.

It is a super-2 number, since 2×18951323749² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18951323696 and 18951323705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18951323719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9475661874 + 9475661875.

It is an arithmetic number, because the mean of its divisors is an integer number (9475661875).

Almost surely, 2^18951323749 is an apocalyptic number.

It is an amenable number.

18951323749 is a deficient number, since it is larger than the sum of its proper divisors (1).

18951323749 is an equidigital number, since it uses as much as digits as its factorization.

18951323749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 52.

The spelling of 18951323749 in words is "eighteen billion, nine hundred fifty-one million, three hundred twenty-three thousand, seven hundred forty-nine".