1221111401 has 4 divisors (see below), whose sum is σ = 1222725252. Its totient is φ = 1219497552.

The previous prime is 1221111373. The next prime is 1221111427. The reversal of 1221111401 is 1041111221.

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 993825625 + 227285776 = 31525^2 + 15076^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221111401 - 2¹⁸ = 1220849257 is a prime.

It is a super-2 number, since 2×1221111401² = 2982226107304365602, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221111431) 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, 805790 + ... + 807303.

It is an arithmetic number, because the mean of its divisors is an integer number (305681313).

Almost surely, 2^1221111401 is an apocalyptic number.

It is an amenable number.

1221111401 is a deficient number, since it is larger than the sum of its proper divisors (1613851).

1221111401 is an equidigital number, since it uses as much as digits as its factorization.

1221111401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1613850.

The product of its (nonzero) digits is 16, while the sum is 14.

The square root of 1221111401 is about 34944.4044304664. The cubic root of 1221111401 is about 1068.8541029837.

Adding to 1221111401 its reverse (1041111221), we get a palindrome (2262222622).

The spelling of 1221111401 in words is "one billion, two hundred twenty-one million, one hundred eleven thousand, four hundred one".