1533249981 has 24 divisors (see below), whose sum is σ = 2346959160. Its totient is φ = 962841600.

The previous prime is 1533249959. The next prime is 1533250099. The reversal of 1533249981 is 1899423351.

It is a happy number.

1533249981 is a `hidden beast` number, since 1 + 53 + 32 + 499 + 81 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 56385081 + 1476864900 = 7509^2 + 38430^2 .

It is not a de Polignac number, because 1533249981 - 2⁷ = 1533249853 is a prime.

It is a super-2 number, since 2×1533249981² = 4701711008473000722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1533249901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60940 + ... + 82341.

It is an arithmetic number, because the mean of its divisors is an integer number (97789965).

Almost surely, 2^1533249981 is an apocalyptic number.

It is an amenable number.

1533249981 is a deficient number, since it is larger than the sum of its proper divisors (813709179).

1533249981 is a wasteful number, since it uses less digits than its factorization.

1533249981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143357 (or 143354 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 1533249981 is about 39156.7360871664. The cubic root of 1533249981 is about 1153.1106661272.

The spelling of 1533249981 in words is "one billion, five hundred thirty-three million, two hundred forty-nine thousand, nine hundred eighty-one".