19997503403 has 4 divisors (see below), whose sum is σ = 20000374128. Its totient is φ = 19994632680.

The previous prime is 19997503399. The next prime is 19997503423. The reversal of 19997503403 is 30430579991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30430579991 = 7 ⋅4347225713.

It is a cyclic number.

It is not a de Polignac number, because 19997503403 - 2² = 19997503399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19997503423) 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, 1424888 + ... + 1438853.

It is an arithmetic number, because the mean of its divisors is an integer number (5000093532).

Almost surely, 2^19997503403 is an apocalyptic number.

19997503403 is a deficient number, since it is larger than the sum of its proper divisors (2870725).

19997503403 is an equidigital number, since it uses as much as digits as its factorization.

19997503403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2870724.

The product of its (nonzero) digits is 918540, while the sum is 50.

The spelling of 19997503403 in words is "nineteen billion, nine hundred ninety-seven million, five hundred three thousand, four hundred three".