1520573981 has 4 divisors (see below), whose sum is σ = 1520676864. Its totient is φ = 1520471100.

The previous prime is 1520573947. The next prime is 1520573983. The reversal of 1520573981 is 1893750251.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1893750251 = 283 ⋅6691697.

It is a cyclic number.

It is not a de Polignac number, because 1520573981 - 2²² = 1516379677 is a prime.

It is a super-2 number, since 2×1520573981² = 4624290463388376722, 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 (1520573983) 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, 24605 + ... + 60386.

It is an arithmetic number, because the mean of its divisors is an integer number (380169216).

Almost surely, 2^1520573981 is an apocalyptic number.

It is an amenable number.

1520573981 is a deficient number, since it is larger than the sum of its proper divisors (102883).

1520573981 is an equidigital number, since it uses as much as digits as its factorization.

1520573981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102882.

The product of its (nonzero) digits is 75600, while the sum is 41.

The square root of 1520573981 is about 38994.5378354456. The cubic root of 1520573981 is about 1149.9241237903.

The spelling of 1520573981 in words is "one billion, five hundred twenty million, five hundred seventy-three thousand, nine hundred eighty-one".