121551000531 has 12 divisors (see below), whose sum is σ = 163909482072. Its totient is φ = 80123490304.

The previous prime is 121551000517. The next prime is 121551000559. The reversal of 121551000531 is 135000155121.

It is a de Polignac number, because none of the positive numbers 2^k-121551000531 is a prime.

It is a super-2 number, since 2×121551000531² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (121551000511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2533806 + ... + 2581331.

It is an arithmetic number, because the mean of its divisors is an integer number (13659123506).

Almost surely, 2^121551000531 is an apocalyptic number.

121551000531 is a deficient number, since it is larger than the sum of its proper divisors (42358481541).

121551000531 is an frugal number, since it uses more digits than its factorization.

121551000531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5115318 (or 5115229 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 24.

Adding to 121551000531 its reverse (135000155121), we get a palindrome (256551155652).

The spelling of 121551000531 in words is "one hundred twenty-one billion, five hundred fifty-one million, five hundred thirty-one", and thus it is an aban number.