661535757126 has 32 divisors (see below), whose sum is σ = 1475936380800. Its totient is φ = 219633381000.

The previous prime is 661535757121. The next prime is 661535757133. The reversal of 661535757126 is 621757535166.

661535757126 is a `hidden beast` number, since 6 + 6 + 1 + 53 + 575 + 7 + 12 + 6 = 666.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661535757121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24390156 + ... + 24417263.

It is an arithmetic number, because the mean of its divisors is an integer number (46123011900).

Almost surely, 2^661535757126 is an apocalyptic number.

661535757126 is an abundant number, since it is smaller than the sum of its proper divisors (814400623674).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661535757126 is a wasteful number, since it uses less digits than its factorization.

661535757126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48807681 (or 48807675 counting only the distinct ones).

The product of its digits is 7938000, while the sum is 54.

The spelling of 661535757126 in words is "six hundred sixty-one billion, five hundred thirty-five million, seven hundred fifty-seven thousand, one hundred twenty-six".