121953437568 has 128 divisors (see below), whose sum is σ = 366723741600. Its totient is φ = 39884083200.

The previous prime is 121953437513. The next prime is 121953437569. The reversal of 121953437568 is 865734359121.

It is a happy number.

121953437568 is a `hidden beast` number, since 1 + 2 + 19 + 5 + 34 + 37 + 568 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-3 number, since 3×121953437568³ (a number of 34 digits) contains 333 as substring.

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 (121953437569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149733 + ... + 516068.

Almost surely, 2^121953437568 is an apocalyptic number.

121953437568 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

121953437568 is an abundant number, since it is smaller than the sum of its proper divisors (244770304032).

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

121953437568 is an equidigital number, since it uses as much as digits as its factorization.

121953437568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 665877 (or 665859 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 54.

The spelling of 121953437568 in words is "one hundred twenty-one billion, nine hundred fifty-three million, four hundred thirty-seven thousand, five hundred sixty-eight".