51487973 has 4 divisors (see below), whose sum is σ = 51503340. Its totient is φ = 51472608.

The previous prime is 51487939. The next prime is 51487981. The reversal of 51487973 is 37978415.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 40742689 + 10745284 = 6383^2 + 3278^2 .

It is a cyclic number.

It is not a de Polignac number, because 51487973 - 2⁸ = 51487717 is a prime.

It is a super-2 number, since 2×51487973² = 5302022727297458, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51487903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 278 + ... + 10151.

It is an arithmetic number, because the mean of its divisors is an integer number (12875835).

Almost surely, 2^51487973 is an apocalyptic number.

It is an amenable number.

51487973 is a deficient number, since it is larger than the sum of its proper divisors (15367).

51487973 is a wasteful number, since it uses less digits than its factorization.

51487973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15366.

The product of its digits is 211680, while the sum is 44.

The square root of 51487973 is about 7175.5120374786. The cubic root of 51487973 is about 372.0219786028.

The spelling of 51487973 in words is "fifty-one million, four hundred eighty-seven thousand, nine hundred seventy-three".