51209798 has 4 divisors (see below), whose sum is σ = 76814700. Its totient is φ = 25604898.

The previous prime is 51209791. The next prime is 51209801. The reversal of 51209798 is 89790215.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×51209798² = 5244886822401608, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51209791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12802448 + ... + 12802451.

It is an arithmetic number, because the mean of its divisors is an integer number (19203675).

Almost surely, 2^51209798 is an apocalyptic number.

51209798 is a deficient number, since it is larger than the sum of its proper divisors (25604902).

51209798 is a wasteful number, since it uses less digits than its factorization.

51209798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25604901.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 51209798 is about 7156.1021513111. The cubic root of 51209798 is about 371.3507917863.

The spelling of 51209798 in words is "fifty-one million, two hundred nine thousand, seven hundred ninety-eight".