51220690 has 8 divisors (see below), whose sum is σ = 92197260. Its totient is φ = 20488272.

The previous prime is 51220639. The next prime is 51220703. The reversal of 51220690 is 9602215.

It can be written as a sum of positive squares in 2 ways, for example, as 46498761 + 4721929 = 6819^2 + 2173^2 .

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

It is a super-2 number, since 2×51220690² = 5247118168152200, which contains 22 as substring.

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 3 ways as a sum of consecutive naturals, for example, 2561025 + ... + 2561044.

Almost surely, 2^51220690 is an apocalyptic number.

51220690 is a deficient number, since it is larger than the sum of its proper divisors (40976570).

51220690 is a wasteful number, since it uses less digits than its factorization.

51220690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5122076.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 51220690 is about 7156.8631396723. The cubic root of 51220690 is about 371.3771179078.

The spelling of 51220690 in words is "fifty-one million, two hundred twenty thousand, six hundred ninety".