51921986 has 8 divisors (see below), whose sum is σ = 78179904. Its totient is φ = 25862020.

The previous prime is 51921983. The next prime is 51921997. The reversal of 51921986 is 68912915.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (51921983) 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, 48830 + ... + 49881.

It is an arithmetic number, because the mean of its divisors is an integer number (9772488).

Almost surely, 2^51921986 is an apocalyptic number.

51921986 is a deficient number, since it is larger than the sum of its proper divisors (26257918).

51921986 is a wasteful number, since it uses less digits than its factorization.

51921986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98976.

The product of its digits is 38880, while the sum is 41.

The square root of 51921986 is about 7205.6912229154. The cubic root of 51921986 is about 373.0643632028.

The spelling of 51921986 in words is "fifty-one million, nine hundred twenty-one thousand, nine hundred eighty-six".