1551111401 has 4 divisors (see below), whose sum is σ = 1772698752. Its totient is φ = 1329524052.

The previous prime is 1551111391. The next prime is 1551111403. The reversal of 1551111401 is 1041111551.

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 1551111401 - 2¹⁸ = 1550849257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1551111403) 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, 110793665 + ... + 110793678.

It is an arithmetic number, because the mean of its divisors is an integer number (443174688).

Almost surely, 2^1551111401 is an apocalyptic number.

It is an amenable number.

1551111401 is a deficient number, since it is larger than the sum of its proper divisors (221587351).

1551111401 is an equidigital number, since it uses as much as digits as its factorization.

1551111401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221587350.

The product of its (nonzero) digits is 100, while the sum is 20.

The square root of 1551111401 is about 39384.1516475854. The cubic root of 1551111401 is about 1157.5710672623.

Adding to 1551111401 its reverse (1041111551), we get a palindrome (2592222952).

The spelling of 1551111401 in words is "one billion, five hundred fifty-one million, one hundred eleven thousand, four hundred one".