1987801 has 4 divisors (see below), whose sum is σ = 1999872. Its totient is φ = 1975732.

The previous prime is 1987789. The next prime is 1987819. The reversal of 1987801 is 1087891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1087891 = 7 ⋅155413.

It is a cyclic number.

It is not a de Polignac number, because 1987801 - 2⁷ = 1987673 is a prime.

It is an Ulam number.

It is a Duffinian number.

1987801 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1987841) 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, 5785 + ... + 6118.

It is an arithmetic number, because the mean of its divisors is an integer number (499968).

2^1987801 is an apocalyptic number.

It is an amenable number.

1987801 is a deficient number, since it is larger than the sum of its proper divisors (12071).

1987801 is a wasteful number, since it uses less digits than its factorization.

1987801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12070.

The product of its (nonzero) digits is 4032, while the sum is 34.

The square root of 1987801 is about 1409.8939676444. The cubic root of 1987801 is about 125.7354194473.

The spelling of 1987801 in words is "one million, nine hundred eighty-seven thousand, eight hundred one".