51489999 has 28 divisors (see below), whose sum is σ = 84230952. Its totient is φ = 31201200.

The previous prime is 51489983. The next prime is 51490001. The reversal of 51489999 is 99998415.

It is not a de Polignac number, because 51489999 - 2⁴ = 51489983 is a prime.

51489999 is a modest number, since divided by 9999 gives 5148 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51489959) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 4809 + ... + 11229.

Almost surely, 2^51489999 is an apocalyptic number.

51489999 is a deficient number, since it is larger than the sum of its proper divisors (32740953).

51489999 is an equidigital number, since it uses as much as digits as its factorization.

51489999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6450 (or 6435 counting only the distinct ones).

The product of its digits is 1049760, while the sum is 54.

The square root of 51489999 is about 7175.6532106840. The cubic root of 51489999 is about 372.0268581024.

The spelling of 51489999 in words is "fifty-one million, four hundred eighty-nine thousand, nine hundred ninety-nine".