1921003537 has 4 divisors (see below), whose sum is σ = 1940023476. Its totient is φ = 1901983600.

The previous prime is 1921003507. The next prime is 1921003547. The reversal of 1921003537 is 7353001291.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7353001291 = 83 ⋅88590377.

It can be written as a sum of positive squares in 2 ways, for example, as 1208327121 + 712676416 = 34761^2 + 26696^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1921003537 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1921003499 and 1921003508.

It is not an unprimeable number, because it can be changed into a prime (1921003507) 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, 9509818 + ... + 9510019.

It is an arithmetic number, because the mean of its divisors is an integer number (485005869).

Almost surely, 2^1921003537 is an apocalyptic number.

It is an amenable number.

1921003537 is a deficient number, since it is larger than the sum of its proper divisors (19019939).

1921003537 is a wasteful number, since it uses less digits than its factorization.

1921003537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19019938.

The product of its (nonzero) digits is 5670, while the sum is 31.

The square root of 1921003537 is about 43829.2543514032. The cubic root of 1921003537 is about 1243.1095079143.

The spelling of 1921003537 in words is "one billion, nine hundred twenty-one million, three thousand, five hundred thirty-seven".