51971642 has 8 divisors (see below), whose sum is σ = 78043476. Its totient is φ = 25957152.

The previous prime is 51971629. The next prime is 51971657. The reversal of 51971642 is 24617915.

It can be written as a sum of positive squares in 2 ways, for example, as 42784681 + 9186961 = 6541^2 + 3031^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11993 + ... + 15740.

Almost surely, 2^51971642 is an apocalyptic number.

51971642 is a deficient number, since it is larger than the sum of its proper divisors (26071834).

51971642 is a wasteful number, since it uses less digits than its factorization.

51971642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28672.

The product of its digits is 15120, while the sum is 35.

The square root of 51971642 is about 7209.1360092594. The cubic root of 51971642 is about 373.1832529906.

The spelling of 51971642 in words is "fifty-one million, nine hundred seventy-one thousand, six hundred forty-two".