19997729750 has 16 divisors (see below), whose sum is σ = 37435750560. Its totient is φ = 7999091800.

The previous prime is 19997729737. The next prime is 19997729761. The reversal of 19997729750 is 5792779991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39995210 + ... + 39995709.

It is an arithmetic number, because the mean of its divisors is an integer number (2339734410).

Almost surely, 2^19997729750 is an apocalyptic number.

19997729750 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19997729750 is a deficient number, since it is larger than the sum of its proper divisors (17438020810).

19997729750 is an equidigital number, since it uses as much as digits as its factorization.

19997729750 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79990936 (or 79990926 counting only the distinct ones).

The product of its (nonzero) digits is 22504230, while the sum is 65.

The spelling of 19997729750 in words is "nineteen billion, nine hundred ninety-seven million, seven hundred twenty-nine thousand, seven hundred fifty".