51501009 has 12 divisors (see below), whose sum is σ = 79879344. Its totient is φ = 29429064.

The previous prime is 51500983. The next prime is 51501031. The reversal of 51501009 is 90010515.

It is a happy number.

It is not a de Polignac number, because 51501009 - 2⁷ = 51500881 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51501059) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 175027 + ... + 175320.

It is an arithmetic number, because the mean of its divisors is an integer number (6656612).

Almost surely, 2^51501009 is an apocalyptic number.

It is an amenable number.

51501009 is a deficient number, since it is larger than the sum of its proper divisors (28378335).

51501009 is a wasteful number, since it uses less digits than its factorization.

51501009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350364 (or 350357 counting only the distinct ones).

The product of its (nonzero) digits is 225, while the sum is 21.

The square root of 51501009 is about 7176.4203472205. The cubic root of 51501009 is about 372.0533727906.

The spelling of 51501009 in words is "fifty-one million, five hundred one thousand, nine".