1997778458 has 8 divisors (see below), whose sum is σ = 3227180628. Its totient is φ = 922051584.

The previous prime is 1997778439. The next prime is 1997778467. The reversal of 1997778458 is 8548777991.

It can be written as a sum of positive squares in 2 ways, for example, as 1677475849 + 320302609 = 40957^2 + 17897^2 .

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

It is a super-2 number, since 2×1997778458² = 7982237534497715528, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1997778394 and 1997778403.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38418791 + ... + 38418842.

Almost surely, 2^1997778458 is an apocalyptic number.

1997778458 is a deficient number, since it is larger than the sum of its proper divisors (1229402170).

1997778458 is a wasteful number, since it uses less digits than its factorization.

1997778458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76837648.

The product of its digits is 35562240, while the sum is 65.

The square root of 1997778458 is about 44696.5150543082. The cubic root of 1997778458 is about 1259.4543824772.

The spelling of 1997778458 in words is "one billion, nine hundred ninety-seven million, seven hundred seventy-eight thousand, four hundred fifty-eight".