1021155554421 has 6 divisors (see below), whose sum is σ = 1475002467510. Its totient is φ = 680770369608.

The previous prime is 1021155554407. The next prime is 1021155554429. The reversal of 1021155554421 is 1244555511201.

1021155554421 is a `hidden beast` number, since 1 + 0 + 2 + 11 + 55 + 554 + 42 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 788474737521 + 232680816900 = 887961^2 + 482370^2 .

It is not a de Polignac number, because 1021155554421 - 2³⁸ = 746277647477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021155554429) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 56730864126 + ... + 56730864143.

It is an arithmetic number, because the mean of its divisors is an integer number (245833744585).

Almost surely, 2^{1021155554421} is an apocalyptic number.

It is an amenable number.

1021155554421 is a deficient number, since it is larger than the sum of its proper divisors (453846913089).

1021155554421 is a wasteful number, since it uses less digits than its factorization.

1021155554421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113461728275 (or 113461728272 counting only the distinct ones).

The product of its (nonzero) digits is 40000, while the sum is 36.

The spelling of 1021155554421 in words is "one trillion, twenty-one billion, one hundred fifty-five million, five hundred fifty-four thousand, four hundred twenty-one".