1999748431 has 2 divisors, whose sum is σ = 1999748432. Its totient is φ = 1999748430.

The previous prime is 1999748383. The next prime is 1999748449. The reversal of 1999748431 is 1348479991.

It is a strong prime.

It is an emirp because it is prime and its reverse (1348479991) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1999748431 is a prime.

It is a super-2 number, since 2×1999748431² = 7997987574573923522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999748831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999874215 + 999874216.

It is an arithmetic number, because the mean of its divisors is an integer number (999874216).

Almost surely, 2^1999748431 is an apocalyptic number.

1999748431 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999748431 is an equidigital number, since it uses as much as digits as its factorization.

1999748431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1959552, while the sum is 55.

The square root of 1999748431 is about 44718.5468346189. The cubic root of 1999748431 is about 1259.8682215000.

The spelling of 1999748431 in words is "one billion, nine hundred ninety-nine million, seven hundred forty-eight thousand, four hundred thirty-one".