401551 has 2 divisors, whose sum is σ = 401552. Its totient is φ = 401550.

The previous prime is 401539. The next prime is 401567. The reversal of 401551 is 155104.

It is a happy number.

It is an a-pointer prime, because the next prime (401567) can be obtained adding 401551 to its sum of digits (16).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 401551 - 2⁵ = 401519 is a prime.

It is a super-2 number, since 2×401551² = 322486411202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200775 + 200776.

It is an arithmetic number, because the mean of its divisors is an integer number (200776).

2⁴⁰¹⁵⁵¹ is an apocalyptic number.

401551 is a deficient number, since it is larger than the sum of its proper divisors (1).

401551 is an equidigital number, since it uses as much as digits as its factorization.

401551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 401551 is about 633.6805188737. The cubic root of 401551 is about 73.7757393639.

Adding to 401551 its reverse (155104), we get a palindrome (556655).

The spelling of 401551 in words is "four hundred one thousand, five hundred fifty-one".