1978000591 has 12 divisors (see below), whose sum is σ = 2301985128. Its totient is φ = 1694658672.

The previous prime is 1978000561. The next prime is 1978000603. The reversal of 1978000591 is 1950008791.

It is a happy number.

It is not a de Polignac number, because 1978000591 - 2¹¹ = 1977998543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978000561) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 117400 + ... + 133186.

It is an arithmetic number, because the mean of its divisors is an integer number (191832094).

Almost surely, 2^1978000591 is an apocalyptic number.

1978000591 is a deficient number, since it is larger than the sum of its proper divisors (323984537).

1978000591 is a wasteful number, since it uses less digits than its factorization.

1978000591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18358 (or 18351 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 40.

The square root of 1978000591 is about 44474.7185600988. The cubic root of 1978000591 is about 1255.2844211797.

The spelling of 1978000591 in words is "one billion, nine hundred seventy-eight million, five hundred ninety-one", and thus it is an aban number.