1551623 has 2 divisors, whose sum is σ = 1551624. Its totient is φ = 1551622.

The previous prime is 1551619. The next prime is 1551647. The reversal of 1551623 is 3261551.

It is a weak prime.

It is an emirp because it is prime and its reverse (3261551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1551623 - 2² = 1551619 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1556623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775811 + 775812.

It is an arithmetic number, because the mean of its divisors is an integer number (775812).

2^1551623 is an apocalyptic number.

1551623 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551623 is an equidigital number, since it uses as much as digits as its factorization.

1551623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 900, while the sum is 23.

The square root of 1551623 is about 1245.6416017459. The cubic root of 1551623 is about 115.7698319481.

The spelling of 1551623 in words is "one million, five hundred fifty-one thousand, six hundred twenty-three".