661387531935 has 16 divisors (see below), whose sum is σ = 1139621593824. Its totient is φ = 325606169472.

The previous prime is 661387531933. The next prime is 661387531939. The reversal of 661387531935 is 539135783166.

It is not a de Polignac number, because 661387531935 - 2¹ = 661387531933 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661387531933) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1695865272 + ... + 1695865661.

It is an arithmetic number, because the mean of its divisors is an integer number (71226349614).

Almost surely, 2^661387531935 is an apocalyptic number.

661387531935 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

661387531935 is a deficient number, since it is larger than the sum of its proper divisors (478234061889).

661387531935 is a wasteful number, since it uses less digits than its factorization.

661387531935 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3391730954.

The product of its digits is 12247200, while the sum is 57.

The spelling of 661387531935 in words is "six hundred sixty-one billion, three hundred eighty-seven million, five hundred thirty-one thousand, nine hundred thirty-five".