1994778291 has 24 divisors (see below), whose sum is σ = 2927670480. Its totient is φ = 1207222720.

The previous prime is 1994778287. The next prime is 1994778301. The reversal of 1994778291 is 1928774991.

It is not a de Polignac number, because 1994778291 - 2² = 1994778287 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1994778241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 277045 + ... + 284153.

It is an arithmetic number, because the mean of its divisors is an integer number (121986270).

Almost surely, 2^1994778291 is an apocalyptic number.

1994778291 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1994778291 is a deficient number, since it is larger than the sum of its proper divisors (932892189).

1994778291 is a wasteful number, since it uses less digits than its factorization.

1994778291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7907 (or 7896 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 57.

The square root of 1994778291 is about 44662.9409130209. The cubic root of 1994778291 is about 1258.8236040686.

The spelling of 1994778291 in words is "one billion, nine hundred ninety-four million, seven hundred seventy-eight thousand, two hundred ninety-one".