1921887 has 24 divisors (see below), whose sum is σ = 3144960. Its totient is φ = 1163160.

The previous prime is 1921883. The next prime is 1921889. The reversal of 1921887 is 7881291.

It is not a de Polignac number, because 1921887 - 2² = 1921883 is a prime.

It is a super-3 number, since 3×1921887³ = 21296331681445833309, which contains 333 as substring.

1921887 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921883) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2314 + ... + 3032.

It is an arithmetic number, because the mean of its divisors is an integer number (131040).

2^1921887 is an apocalyptic number.

1921887 is a deficient number, since it is larger than the sum of its proper divisors (1223073).

1921887 is an equidigital number, since it uses as much as digits as its factorization.

1921887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 745 (or 733 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 1921887 is about 1386.3213913087. The cubic root of 1921887 is about 124.3300045988.

The spelling of 1921887 in words is "one million, nine hundred twenty-one thousand, eight hundred eighty-seven".