6521161545 has 24 divisors (see below), whose sum is σ = 11408993856. Its totient is φ = 3445446048.

The previous prime is 6521161541. The next prime is 6521161553. The reversal of 6521161545 is 5451611256.

6521161545 is a `hidden beast` number, since 6 + 52 + 1 + 1 + 61 + 545 = 666.

It is not a de Polignac number, because 6521161545 - 2² = 6521161541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6521161541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 672357 + ... + 681986.

It is an arithmetic number, because the mean of its divisors is an integer number (475374744).

Almost surely, 2^6521161545 is an apocalyptic number.

It is an amenable number.

6521161545 is a deficient number, since it is larger than the sum of its proper divisors (4887832311).

6521161545 is a wasteful number, since it uses less digits than its factorization.

6521161545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1354461 (or 1354458 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The square root of 6521161545 is about 80753.7091717774. The cubic root of 6521161545 is about 1868.2786589633.

It can be divided in two parts, 65211 and 61545, that added together give a triangular number (126756 = T₅₀₃).

The spelling of 6521161545 in words is "six billion, five hundred twenty-one million, one hundred sixty-one thousand, five hundred forty-five".