51721671 has 16 divisors (see below), whose sum is σ = 73115648. Its totient is φ = 32464800.

The previous prime is 51721669. The next prime is 51721673. The reversal of 51721671 is 17612715.

It is an interprime number because it is at equal distance from previous prime (51721669) and next prime (51721673).

It is not a de Polignac number, because 51721671 - 2¹ = 51721669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51721673) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4075 + ... + 10956.

It is an arithmetic number, because the mean of its divisors is an integer number (4569728).

Almost surely, 2^51721671 is an apocalyptic number.

51721671 is a deficient number, since it is larger than the sum of its proper divisors (21393977).

51721671 is a wasteful number, since it uses less digits than its factorization.

51721671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15102.

The product of its digits is 2940, while the sum is 30.

The square root of 51721671 is about 7191.7780138155. The cubic root of 51721671 is about 372.5839841864.

The spelling of 51721671 in words is "fifty-one million, seven hundred twenty-one thousand, six hundred seventy-one".