7121557145042 has 4 divisors (see below), whose sum is σ = 10682335717566. Its totient is φ = 3560778572520.

The previous prime is 7121557144997. The next prime is 7121557145051. The reversal of 7121557145042 is 2405417551217.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 4946082592441 + 2175474552601 = 2223979^2 + 1474949^2 .

It is a junction number, because it is equal to n+sod(n) for n = 7121557144984 and 7121557145002.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1780389286259 + ... + 1780389286262.

Almost surely, 2^{7121557145042} is an apocalyptic number.

7121557145042 is a deficient number, since it is larger than the sum of its proper divisors (3560778572524).

7121557145042 is a wasteful number, since it uses less digits than its factorization.

7121557145042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3560778572523.

The product of its (nonzero) digits is 392000, while the sum is 44.

The spelling of 7121557145042 in words is "seven trillion, one hundred twenty-one billion, five hundred fifty-seven million, one hundred forty-five thousand, forty-two".