221012255501 has 4 divisors (see below), whose sum is σ = 221038799100. Its totient is φ = 220985711904.

The previous prime is 221012255491. The next prime is 221012255509. The reversal of 221012255501 is 105552210122.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 144684379876 + 76327875625 = 380374^2 + 276275^2 .

It is a cyclic number.

It is not a de Polignac number, because 221012255501 - 2¹⁴ = 221012239117 is a prime.

It is a super-2 number, since 2×221012255501² (a number of 23 digits) contains 22 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 (221012255509) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13259306 + ... + 13275963.

It is an arithmetic number, because the mean of its divisors is an integer number (55259699775).

Almost surely, 2^221012255501 is an apocalyptic number.

It is an amenable number.

221012255501 is a deficient number, since it is larger than the sum of its proper divisors (26543599).

221012255501 is an equidigital number, since it uses as much as digits as its factorization.

221012255501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26543598.

The product of its (nonzero) digits is 2000, while the sum is 26.

Adding to 221012255501 its reverse (105552210122), we get a palindrome (326564465623).

The spelling of 221012255501 in words is "two hundred twenty-one billion, twelve million, two hundred fifty-five thousand, five hundred one".