120021561511 has 4 divisors (see below), whose sum is σ = 120032314792. Its totient is φ = 120010808232.

The previous prime is 120021561509. The next prime is 120021561523. The reversal of 120021561511 is 115165120021.

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

It is a cyclic number.

It is not a de Polignac number, because 120021561511 - 2¹ = 120021561509 is a prime.

It is a super-3 number, since 3×120021561511³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120021561811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5359881 + ... + 5382226.

It is an arithmetic number, because the mean of its divisors is an integer number (30008078698).

Almost surely, 2^120021561511 is an apocalyptic number.

120021561511 is a deficient number, since it is larger than the sum of its proper divisors (10753281).

120021561511 is a wasteful number, since it uses less digits than its factorization.

120021561511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10753280.

The product of its (nonzero) digits is 600, while the sum is 25.

Adding to 120021561511 its reverse (115165120021), we get a palindrome (235186681532).

The spelling of 120021561511 in words is "one hundred twenty billion, twenty-one million, five hundred sixty-one thousand, five hundred eleven".