1997626 has 4 divisors (see below), whose sum is σ = 2996442. Its totient is φ = 998812.

The previous prime is 1997617. The next prime is 1997647. The reversal of 1997626 is 6267991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6267991 = 2459 ⋅2549.

It can be written as a sum of positive squares in only one way, i.e., 1104601 + 893025 = 1051^2 + 945^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499405 + ... + 499408.

2^1997626 is an apocalyptic number.

1997626 is a deficient number, since it is larger than the sum of its proper divisors (998816).

1997626 is an equidigital number, since it uses as much as digits as its factorization.

1997626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 998815.

The product of its digits is 40824, while the sum is 40.

The square root of 1997626 is about 1413.3739774030. The cubic root of 1997626 is about 125.9422343759.

It can be divided in two parts, 19976 and 26, that added together give a palindrome (20002).

The spelling of 1997626 in words is "one million, nine hundred ninety-seven thousand, six hundred twenty-six".