51021705 has 64 divisors (see below), whose sum is σ = 100159488. Its totient is φ = 21669120.

The previous prime is 51021697. The next prime is 51021713. The reversal of 51021705 is 50712015.

It is an interprime number because it is at equal distance from previous prime (51021697) and next prime (51021713).

It is not a de Polignac number, because 51021705 - 2³ = 51021697 is a prime.

It is a super-2 number, since 2×51021705² = 5206428762214050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

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 63 ways as a sum of consecutive naturals, for example, 89070 + ... + 89640.

It is an arithmetic number, because the mean of its divisors is an integer number (1564992).

Almost surely, 2^51021705 is an apocalyptic number.

It is an amenable number.

51021705 is a deficient number, since it is larger than the sum of its proper divisors (49137783).

51021705 is a wasteful number, since it uses less digits than its factorization.

51021705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646.

The product of its (nonzero) digits is 350, while the sum is 21.

The square root of 51021705 is about 7142.9479208517. The cubic root of 51021705 is about 370.8955782679.

The spelling of 51021705 in words is "fifty-one million, twenty-one thousand, seven hundred five".