21001011212001 has 16 divisors (see below), whose sum is σ = 29597406808640. Its totient is φ = 13208760046080.

The previous prime is 21001011211967. The next prime is 21001011212021. The reversal of 21001011212001 is 10021211010012.

It is not a de Polignac number, because 21001011212001 - 2³⁰ = 20999937470177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001011212021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 764382100 + ... + 764409573.

It is an arithmetic number, because the mean of its divisors is an integer number (1849837925540).

Almost surely, 2^{21001011212001} is an apocalyptic number.

It is an amenable number.

21001011212001 is a deficient number, since it is larger than the sum of its proper divisors (8596395596639).

21001011212001 is a wasteful number, since it uses less digits than its factorization.

21001011212001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1528791936.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21001011212001 its reverse (10021211010012), we get a palindrome (31022222222013).

The spelling of 21001011212001 in words is "twenty-one trillion, one billion, eleven million, two hundred twelve thousand, one".