51691080 has 192 divisors, whose sum is σ = 184680000. Its totient is φ = 11536896.

The previous prime is 51691069. The next prime is 51691091. The reversal of 51691080 is 8019615.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (51691069) and next prime (51691091).

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 47 ways as a sum of consecutive naturals, for example, 346846 + ... + 346994.

It is an arithmetic number, because the mean of its divisors is an integer number (961875).

Almost surely, 2^51691080 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51691080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92340000).

51691080 is an abundant number, since it is smaller than the sum of its proper divisors (132988920).

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

51691080 is a wasteful number, since it uses less digits than its factorization.

51691080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 225 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 30.

The square root of 51691080 is about 7189.6508955581. The cubic root of 51691080 is about 372.5105142446.

The spelling of 51691080 in words is "fifty-one million, six hundred ninety-one thousand, eighty".