19891955 has 32 divisors (see below), whose sum is σ = 27086400. Its totient is φ = 13934592.

The previous prime is 19891939. The next prime is 19891961. The reversal of 19891955 is 55919891.

It is a cyclic number.

It is not a de Polignac number, because 19891955 - 2⁴ = 19891939 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 175979 + ... + 176091.

It is an arithmetic number, because the mean of its divisors is an integer number (846450).

Almost surely, 2^19891955 is an apocalyptic number.

19891955 is a deficient number, since it is larger than the sum of its proper divisors (7194445).

19891955 is a wasteful number, since it uses less digits than its factorization.

19891955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263.

The product of its digits is 145800, while the sum is 47.

The square root of 19891955 is about 4460.0397980287. The cubic root of 19891955 is about 270.9520800516.

The spelling of 19891955 in words is "nineteen million, eight hundred ninety-one thousand, nine hundred fifty-five".