1977998 has 8 divisors (see below), whose sum is σ = 3236760. Its totient is φ = 899080.

The previous prime is 1977991. The next prime is 1978021. The reversal of 1977998 is 8997791.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1977991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44933 + ... + 44976.

It is an arithmetic number, because the mean of its divisors is an integer number (404595).

2^1977998 is an apocalyptic number.

1977998 is a deficient number, since it is larger than the sum of its proper divisors (1258762).

1977998 is a wasteful number, since it uses less digits than its factorization.

1977998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89922.

The product of its digits is 285768, while the sum is 50.

The square root of 1977998 is about 1406.4131683115. The cubic root of 1977998 is about 125.5283873077.

The spelling of 1977998 in words is "one million, nine hundred seventy-seven thousand, nine hundred ninety-eight".