21001120022001 has 64 divisors (see below), whose sum is σ = 32833293244416. Its totient is φ = 11689721971200.

The previous prime is 21001120021993. The next prime is 21001120022009. The reversal of 21001120022001 is 10022002110012.

It is an interprime number because it is at equal distance from previous prime (21001120021993) and next prime (21001120022009).

It is not a de Polignac number, because 21001120022001 - 2³ = 21001120021993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21001120022009) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1610138386 + ... + 1610151428.

It is an arithmetic number, because the mean of its divisors is an integer number (513020206944).

Almost surely, 2^{21001120022001} is an apocalyptic number.

21001120022001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21001120022001 is a deficient number, since it is larger than the sum of its proper divisors (11832173222415).

21001120022001 is a wasteful number, since it uses less digits than its factorization.

21001120022001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15862.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21001120022001 its reverse (10022002110012), we get a palindrome (31023122132013).

The spelling of 21001120022001 in words is "twenty-one trillion, one billion, one hundred twenty million, twenty-two thousand, one".