1551919 has 2 divisors, whose sum is σ = 1551920. Its totient is φ = 1551918.

The previous prime is 1551917. The next prime is 1551929. The reversal of 1551919 is 9191551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1551919 - 2¹ = 1551917 is a prime.

It is a super-2 number, since 2×1551919² = 4816905165122, which contains 22 as substring.

Together with 1551917, it forms a pair of twin primes.

It is equal to p₁₁₇₇₉₆ and since 1551919 and 117796 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1551911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775959 + 775960.

It is an arithmetic number, because the mean of its divisors is an integer number (775960).

2^1551919 is an apocalyptic number.

1551919 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551919 is an equidigital number, since it uses as much as digits as its factorization.

1551919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2025, while the sum is 31.

The square root of 1551919 is about 1245.7604103518. The cubic root of 1551919 is about 115.7771932061. Note that the first 3 decimals are identical.

The spelling of 1551919 in words is "one million, five hundred fifty-one thousand, nine hundred nineteen".