1997951 has 4 divisors (see below), whose sum is σ = 2000904. Its totient is φ = 1995000.

The previous prime is 1997939. The next prime is 1997969. The reversal of 1997951 is 1597991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1597991 = 449 ⋅3559.

It is a cyclic number.

It is not a de Polignac number, because 1997951 - 2⁶ = 1997887 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 1997899 and 1997908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1997911) 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, 101 + ... + 2001.

It is an arithmetic number, because the mean of its divisors is an integer number (500226).

2^1997951 is an apocalyptic number.

1997951 is a deficient number, since it is larger than the sum of its proper divisors (2953).

1997951 is a wasteful number, since it uses less digits than its factorization.

1997951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2952.

The product of its digits is 25515, while the sum is 41.

The square root of 1997951 is about 1413.4889458358. The cubic root of 1997951 is about 125.9490639838.

The spelling of 1997951 in words is "one million, nine hundred ninety-seven thousand, nine hundred fifty-one".