51201665220 has 96 divisors (see below), whose sum is σ = 156694680576. Its totient is φ = 12436070400.

The previous prime is 51201665209. The next prime is 51201665231. The reversal of 51201665220 is 2256610215.

It is an interprime number because it is at equal distance from previous prime (51201665209) and next prime (51201665231).

It is a super-2 number, since 2×51201665220² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 778021 + ... + 841260.

It is an arithmetic number, because the mean of its divisors is an integer number (1632236256).

Almost surely, 2^51201665220 is an apocalyptic number.

It is an amenable number.

51201665220 is an abundant number, since it is smaller than the sum of its proper divisors (105493015356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51201665220 is a wasteful number, since it uses less digits than its factorization.

51201665220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1619341 (or 1619339 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 51201665220 in words is "fifty-one billion, two hundred one million, six hundred sixty-five thousand, two hundred twenty".