51689040 has 80 divisors (see below), whose sum is σ = 172572288. Its totient is φ = 12722688.

The previous prime is 51689039. The next prime is 51689047. The reversal of 51689040 is 4098615.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×51689040² = 5343513712243200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51688992 and 51689010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51689047) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 5164 + ... + 11403.

Almost surely, 2^51689040 is an apocalyptic number.

It is an amenable number.

51689040 is an abundant number, since it is smaller than the sum of its proper divisors (120883248).

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

51689040 is a wasteful number, since it uses less digits than its factorization.

51689040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16596 (or 16590 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 51689040 is about 7189.5090235704. The cubic root of 51689040 is about 372.5056137766.

The spelling of 51689040 in words is "fifty-one million, six hundred eighty-nine thousand, forty".