121155401856 has 64 divisors (see below), whose sum is σ = 321889258080. Its totient is φ = 40376322048.

The previous prime is 121155401813. The next prime is 121155401981. The reversal of 121155401856 is 658104551121.

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1863855 + ... + 1927761.

Almost surely, 2^121155401856 is an apocalyptic number.

121155401856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

121155401856 is an abundant number, since it is smaller than the sum of its proper divisors (200733856224).

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

121155401856 is an equidigital number, since it uses as much as digits as its factorization.

121155401856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68861 (or 68849 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 39.

Adding to 121155401856 its reverse (658104551121), we get a palindrome (779259952977).

The spelling of 121155401856 in words is "one hundred twenty-one billion, one hundred fifty-five million, four hundred one thousand, eight hundred fifty-six".