21120000011001 has 24 divisors (see below), whose sum is σ = 30539417617800. Its totient is φ = 14064887429376.

The previous prime is 21120000010999. The next prime is 21120000011017. The reversal of 21120000011001 is 10011000002112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 10827067783401 + 10292932227600 = 3290451^2 + 3208260^2 .

It is not a de Polignac number, because 21120000011001 - 2¹ = 21120000010999 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21120000011041) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81034171 + ... + 81294383.

It is an arithmetic number, because the mean of its divisors is an integer number (1272475734075).

Almost surely, 2^{21120000011001} is an apocalyptic number.

It is an amenable number.

21120000011001 is a deficient number, since it is larger than the sum of its proper divisors (9419417606799).

21120000011001 is a wasteful number, since it uses less digits than its factorization.

21120000011001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269865 (or 269862 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21120000011001 its reverse (10011000002112), we get a palindrome (31131000013113).

The spelling of 21120000011001 in words is "twenty-one trillion, one hundred twenty billion, eleven thousand, one".