1542039920521 has 3 divisors (see below), whose sum is σ = 1542041162311. Its totient is φ = 1542038678732.

The previous prime is 1542039920513. The next prime is 1542039920539. The reversal of 1542039920521 is 1250299302451.

The square root of 1542039920521 is 1241789.

It is a perfect power (a square), and thus also a powerful number.

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.

It can be written as a sum of positive squares in only one way, i.e., 864414608121 + 677625312400 = 929739^2 + 823180^2 .

It is not a de Polignac number, because 1542039920521 - 2³ = 1542039920513 is a prime.

It is a super-2 number, since 2×1542039920521² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1542039920821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 620895 + ... + 1862683.

Almost surely, 2^{1542039920521} is an apocalyptic number.

1542039920521 is the 1241789-th square number.

1542039920521 is the 620895-th centered octagonal number.

It is an amenable number.

1542039920521 is a deficient number, since it is larger than the sum of its proper divisors (1241790).

1542039920521 is an frugal number, since it uses more digits than its factorization.

1542039920521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2483578 (or 1241789 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 43.

The spelling of 1542039920521 in words is "one trillion, five hundred forty-two billion, thirty-nine million, nine hundred twenty thousand, five hundred twenty-one".