1221243001 has 4 divisors (see below), whose sum is σ = 1332265104. Its totient is φ = 1110220900.

The previous prime is 1221242989. The next prime is 1221243007. The reversal of 1221243001 is 1003421221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1221243001 - 2⁷ = 1221242873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221243007) 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, 55511035 + ... + 55511056.

It is an arithmetic number, because the mean of its divisors is an integer number (333066276).

Almost surely, 2^1221243001 is an apocalyptic number.

1221243001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221243001 is a deficient number, since it is larger than the sum of its proper divisors (111022103).

1221243001 is a wasteful number, since it uses less digits than its factorization.

1221243001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111022102.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 1221243001 is about 34946.2873707637. The cubic root of 1221243001 is about 1068.8924986471.

Adding to 1221243001 its reverse (1003421221), we get a palindrome (2224664222).

The spelling of 1221243001 in words is "one billion, two hundred twenty-one million, two hundred forty-three thousand, one".