1921538007 has 24 divisors (see below), whose sum is σ = 2867424768. Its totient is φ = 1238691600.

The previous prime is 1921537973. The next prime is 1921538011. The reversal of 1921538007 is 7008351291.

It is not a de Polignac number, because 1921538007 - 2¹⁰ = 1921536983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921536007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 503368 + ... + 507170.

It is an arithmetic number, because the mean of its divisors is an integer number (119476032).

Almost surely, 2^1921538007 is an apocalyptic number.

1921538007 is a deficient number, since it is larger than the sum of its proper divisors (945886761).

1921538007 is a wasteful number, since it uses less digits than its factorization.

1921538007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5651 (or 5648 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The square root of 1921538007 is about 43835.3511107188. The cubic root of 1921538007 is about 1243.2247850108.

Adding to 1921538007 its reverse (7008351291), we get a palindrome (8929889298).

The spelling of 1921538007 in words is "one billion, nine hundred twenty-one million, five hundred thirty-eight thousand, seven".