51821427 has 16 divisors (see below), whose sum is σ = 79107840. Its totient is φ = 29559072.

The previous prime is 51821387. The next prime is 51821431. The reversal of 51821427 is 72412815.

It is not a de Polignac number, because 51821427 - 2¹¹ = 51819379 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51821394 and 51821403.

It is not an unprimeable number, because it can be changed into a prime (51821447) 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, 11824 + ... + 15602.

It is an arithmetic number, because the mean of its divisors is an integer number (4944240).

Almost surely, 2^51821427 is an apocalyptic number.

51821427 is a deficient number, since it is larger than the sum of its proper divisors (27286413).

51821427 is a wasteful number, since it uses less digits than its factorization.

51821427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4442.

The product of its digits is 4480, while the sum is 30.

The square root of 51821427 is about 7198.7100927875. The cubic root of 51821427 is about 372.8233655888.

It can be divided in two parts, 518 and 21427, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 51821427 in words is "fifty-one million, eight hundred twenty-one thousand, four hundred twenty-seven".