19905217234 has 32 divisors (see below), whose sum is σ = 34305828480. Its totient is φ = 8485233408.

The previous prime is 19905217181. The next prime is 19905217237. The reversal of 19905217234 is 43271250991.

It is a super-2 number, since 2×19905217234² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19905217237) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4155789 + ... + 4160575.

It is an arithmetic number, because the mean of its divisors is an integer number (1072057140).

Almost surely, 2^19905217234 is an apocalyptic number.

19905217234 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

19905217234 is a deficient number, since it is larger than the sum of its proper divisors (14400611246).

19905217234 is a wasteful number, since it uses less digits than its factorization.

19905217234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6322.

The product of its (nonzero) digits is 136080, while the sum is 43.

The spelling of 19905217234 in words is "nineteen billion, nine hundred five million, two hundred seventeen thousand, two hundred thirty-four".