51901690 has 8 divisors (see below), whose sum is σ = 93423060. Its totient is φ = 20760672.

The previous prime is 51901687. The next prime is 51901721. The reversal of 51901690 is 9610915.

It can be written as a sum of positive squares in 2 ways, for example, as 48149721 + 3751969 = 6939^2 + 1937^2 .

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

It is a super-2 number, since 2×51901690² = 5387570849712200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2595075 + ... + 2595094.

Almost surely, 2^51901690 is an apocalyptic number.

51901690 is a deficient number, since it is larger than the sum of its proper divisors (41521370).

51901690 is a wasteful number, since it uses less digits than its factorization.

51901690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5190176.

The product of its (nonzero) digits is 2430, while the sum is 31.

The square root of 51901690 is about 7204.2827540290. The cubic root of 51901690 is about 373.0157473101.

The spelling of 51901690 in words is "fifty-one million, nine hundred one thousand, six hundred ninety".