1921487 has 4 divisors (see below), whose sum is σ = 1924296. Its totient is φ = 1918680.

The previous prime is 1921483. The next prime is 1921499. The reversal of 1921487 is 7841291.

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: 7841291 = 41 ⋅191251.

It is a cyclic number.

It is not a de Polignac number, because 1921487 - 2² = 1921483 is a prime.

It is a super-2 number, since 2×1921487² = 7384224582338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 368 + ... + 1994.

It is an arithmetic number, because the mean of its divisors is an integer number (481074).

2^1921487 is an apocalyptic number.

1921487 is a deficient number, since it is larger than the sum of its proper divisors (2809).

1921487 is a wasteful number, since it uses less digits than its factorization.

1921487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2808.

The product of its digits is 4032, while the sum is 32.

The square root of 1921487 is about 1386.1771171102. The cubic root of 1921487 is about 124.3213784495.

The spelling of 1921487 in words is "one million, nine hundred twenty-one thousand, four hundred eighty-seven".