2191389478 has 16 divisors (see below), whose sum is σ = 3396197376. Its totient is φ = 1059818760.

The previous prime is 2191389457. The next prime is 2191389481. The reversal of 2191389478 is 8749831912.

2191389478 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×2191389478² = 9604375688578224968, which contains 22 as substring.

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, 114838 + ... + 132553.

It is an arithmetic number, because the mean of its divisors is an integer number (212262336).

Almost surely, 2^2191389478 is an apocalyptic number.

2191389478 is a deficient number, since it is larger than the sum of its proper divisors (1204807898).

2191389478 is a wasteful number, since it uses less digits than its factorization.

2191389478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247539.

The product of its digits is 870912, while the sum is 52.

The square root of 2191389478 is about 46812.2791369957. The cubic root of 2191389478 is about 1298.8924448348.

The spelling of 2191389478 in words is "two billion, one hundred ninety-one million, three hundred eighty-nine thousand, four hundred seventy-eight".