1535519983921 has 105 divisors (see below), whose sum is σ = 2079633756777. Its totient is φ = 1133534916360.

The previous prime is 1535519983909. The next prime is 1535519983969. The reversal of 1535519983921 is 1293899155351.

The square root of 1535519983921 is 1239161.

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

It is not a de Polignac number, because 1535519983921 - 2⁵ = 1535519983889 is a prime.

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 1535519983921.

It is not an unprimeable number, because it can be changed into a prime (1535519987921) by changing a digit.

It is a polite number, since it can be written in 104 ways as a sum of consecutive naturals, for example, 80816841250 + ... + 80816841268.

Almost surely, 2^{1535519983921} is an apocalyptic number.

1535519983921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1535519983921 is the 1239161-st square number.

1535519983921 is the 619581-st centered octagonal number.

It is an amenable number.

1535519983921 is a deficient number, since it is larger than the sum of its proper divisors (544113772856).

1535519983921 is an frugal number, since it uses more digits than its factorization.

1535519983921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132 (or 37 counting only the distinct ones).

The product of its digits is 13122000, while the sum is 61.

The spelling of 1535519983921 in words is "one trillion, five hundred thirty-five billion, five hundred nineteen million, nine hundred eighty-three thousand, nine hundred twenty-one".