1551 has 8 divisors (see below), whose sum is σ = 2304. Its totient is φ = 920.

The previous prime is 1549. The next prime is 1553.

1551 = T₁₁ + T₁₂ + ... + T₂₁.

1551 is nontrivially palindromic in base 10 and base 15.

It is an interprime number because it is at equal distance from previous prime (1549) and next prime (1553).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1551 - 2¹ = 1549 is a prime.

1551 is an undulating number in base 15.

It is a nialpdrome in base 12.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10 + ... + 56.

It is an arithmetic number, because the mean of its divisors is an integer number (288).

1551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1551 is a deficient number, since it is larger than the sum of its proper divisors (753).

1551 is a wasteful number, since it uses less digits than its factorization.

1551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61.

The product of its digits is 25, while the sum is 12.

The square root of 1551 is about 39.3827373350. The cubic root of 1551 is about 11.5754335430.

It can be divided in two parts, 15 and 51, that added together give a palindrome (66).

The spelling of 1551 in words is "one thousand, five hundred fifty-one".