51897615 has 80 divisors (see below), whose sum is σ = 106482816. Its totient is φ = 21403200.

The previous prime is 51897613. The next prime is 51897631. The reversal of 51897615 is 51679815.

It is a Cunningham number, because it is equal to 7204²-1.

It is not a de Polignac number, because 51897615 - 2¹ = 51897613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51897611) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 396100 + ... + 396230.

Almost surely, 2^51897615 is an apocalyptic number.

51897615 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

51897615 is an abundant number, since it is smaller than the sum of its proper divisors (54585201).

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

51897615 is a wasteful number, since it uses less digits than its factorization.

51897615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178 (or 157 counting only the distinct ones).

The product of its digits is 75600, while the sum is 42.

The square root of 51897615 is about 7203.9999305941. Note that the first 4 decimals coincide. The cubic root of 51897615 is about 373.0059847574.

The spelling of 51897615 in words is "fifty-one million, eight hundred ninety-seven thousand, six hundred fifteen".