51621001 has 8 divisors (see below), whose sum is σ = 52452680. Its totient is φ = 50792832.

The previous prime is 51620981. The next prime is 51621007. The reversal of 51621001 is 10012615.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1904400 + 49716601 = 1380^2 + 7051^2 .

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 51621001 - 2⁹ = 51620489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51621007) 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, 60091 + ... + 60943.

It is an arithmetic number, because the mean of its divisors is an integer number (6556585).

Almost surely, 2^51621001 is an apocalyptic number.

It is an amenable number.

51621001 is a deficient number, since it is larger than the sum of its proper divisors (831679).

51621001 is an equidigital number, since it uses as much as digits as its factorization.

51621001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1755.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 51621001 is about 7184.7756401992. The cubic root of 51621001 is about 372.3420972413.

Adding to 51621001 its reverse (10012615), we get a palindrome (61633616).

The spelling of 51621001 in words is "fifty-one million, six hundred twenty-one thousand, one".