121220111221542 has 80 divisors (see below), whose sum is σ = 277416345286080. Its totient is φ = 39544948852992.

The previous prime is 121220111221541. The next prime is 121220111221553. The reversal of 121220111221542 is 245122111022121.

121220111221542 is a `hidden beast` number, since 1 + 2 + 1 + 2 + 2 + 0 + 1 + 112 + 2 + 1 + 542 = 666.

It is a super-2 number, since 2×121220111221542² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121220111221541) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 151034608 + ... + 151835084.

It is an arithmetic number, because the mean of its divisors is an integer number (3467704316076).

Almost surely, 2^{121220111221542} is an apocalyptic number.

121220111221542 is an abundant number, since it is smaller than the sum of its proper divisors (156196234064538).

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

121220111221542 is a wasteful number, since it uses less digits than its factorization.

121220111221542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820427 (or 820418 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

Adding to 121220111221542 its reverse (245122111022121), we get a palindrome (366342222243663).

The spelling of 121220111221542 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty-one thousand, five hundred forty-two".