121543501995 has 16 divisors (see below), whose sum is σ = 216077337120. Its totient is φ = 64823200992.

The previous prime is 121543501991. The next prime is 121543502071. The reversal of 121543501995 is 599105345121.

121543501995 is a `hidden beast` number, since 1 + 2 + 1 + 54 + 3 + 501 + 9 + 95 = 666.

It is not a de Polignac number, because 121543501995 - 2² = 121543501991 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 121543501995.

It is not an unprimeable number, because it can be changed into a prime (121543501991) 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, 450160984 + ... + 450161253.

It is an arithmetic number, because the mean of its divisors is an integer number (13504833570).

Almost surely, 2^121543501995 is an apocalyptic number.

121543501995 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121543501995 is a deficient number, since it is larger than the sum of its proper divisors (94533835125).

121543501995 is an equidigital number, since it uses as much as digits as its factorization.

121543501995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900322251 (or 900322245 counting only the distinct ones).

The product of its (nonzero) digits is 243000, while the sum is 45.

The spelling of 121543501995 in words is "one hundred twenty-one billion, five hundred forty-three million, five hundred one thousand, nine hundred ninety-five".