221012001 has 36 divisors (see below), whose sum is σ = 379297152. Its totient is φ = 123593904.

The previous prime is 221011993. The next prime is 221012039. The reversal of 221012001 is 100210122.

It is not a de Polignac number, because 221012001 - 2³ = 221011993 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 (221012081) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 15396 + ... + 26058.

It is an arithmetic number, because the mean of its divisors is an integer number (10536032).

Almost surely, 2^221012001 is an apocalyptic number.

221012001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221012001 is a deficient number, since it is larger than the sum of its proper divisors (158285151).

221012001 is a wasteful number, since it uses less digits than its factorization.

221012001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10730 (or 10720 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 221012001 is about 14866.4723791490. The cubic root of 221012001 is about 604.6053031994.

Adding to 221012001 its reverse (100210122), we get a palindrome (321222123).

The spelling of 221012001 in words is "two hundred twenty-one million, twelve thousand, one".