133537461217281 has 81 divisors (see below), whose sum is σ = 214652850061377. Its totient is φ = 79937761234320.

The previous prime is 133537461217271. The next prime is 133537461217309. The reversal of 133537461217281 is 182712164735331.

The square root of 133537461217281 is 11555841.

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

133537461217281 is a `hidden beast` number, since 1 + 3 + 3 + 5 + 3 + 7 + 4 + 612 + 17 + 2 + 8 + 1 = 666.

It is not a de Polignac number, because 133537461217281 - 2²¹ = 133537459120129 is a prime.

It is a super-2 number, since 2×133537461217281² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (133537461217261) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 31651446390 + ... + 31651450608.

Almost surely, 2^{133537461217281} is an apocalyptic number.

133537461217281 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

133537461217281 is the 11555841-st square number.

133537461217281 is the 5777921-st centered octagonal number.

It is an amenable number.

133537461217281 is a deficient number, since it is larger than the sum of its proper divisors (81115388844096).

133537461217281 is an frugal number, since it uses more digits than its factorization.

133537461217281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8632 (or 4316 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 54.

The spelling of 133537461217281 in words is "one hundred thirty-three trillion, five hundred thirty-seven billion, four hundred sixty-one million, two hundred seventeen thousand, two hundred eighty-one".