51820715 has 4 divisors (see below), whose sum is σ = 62184864. Its totient is φ = 41456568.

The previous prime is 51820687. The next prime is 51820721. The reversal of 51820715 is 51702815.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51702815 = 5 ⋅10340563.

It is a cyclic number.

It is not a de Polignac number, because 51820715 - 2⁸ = 51820459 is a prime.

It is a super-2 number, since 2×51820715² = 5370773006222450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5182067 + ... + 5182076.

It is an arithmetic number, because the mean of its divisors is an integer number (15546216).

Almost surely, 2^51820715 is an apocalyptic number.

51820715 is a deficient number, since it is larger than the sum of its proper divisors (10364149).

51820715 is a wasteful number, since it uses less digits than its factorization.

51820715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10364148.

The product of its (nonzero) digits is 2800, while the sum is 29.

The square root of 51820715 is about 7198.6606393134. The cubic root of 51820715 is about 372.8216581133.

The spelling of 51820715 in words is "fifty-one million, eight hundred twenty thousand, seven hundred fifteen".