1921007 has 4 divisors (see below), whose sum is σ = 2095656. Its totient is φ = 1746360.

The previous prime is 1920991. The next prime is 1921013. The reversal of 1921007 is 7001291.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1921007 - 2⁴ = 1920991 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1921007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921027) 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, 87308 + ... + 87329.

It is an arithmetic number, because the mean of its divisors is an integer number (523914).

2^1921007 is an apocalyptic number.

1921007 is a deficient number, since it is larger than the sum of its proper divisors (174649).

1921007 is a wasteful number, since it uses less digits than its factorization.

1921007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174648.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 1921007 is about 1386.0039682483. The cubic root of 1921007 is about 124.3110254900.

Adding to 1921007 its reverse (7001291), we get a palindrome (8922298).

The spelling of 1921007 in words is "one million, nine hundred twenty-one thousand, seven".