51997019 has 4 divisors (see below), whose sum is σ = 53206296. Its totient is φ = 50787744.

The previous prime is 51997009. The next prime is 51997027. The reversal of 51997019 is 91079915.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91079915 = 5 ⋅18215983.

It is a cyclic number.

It is not a de Polignac number, because 51997019 - 2¹⁶ = 51931483 is a prime.

It is a super-2 number, since 2×51997019² = 5407379969772722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51997009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 604574 + ... + 604659.

It is an arithmetic number, because the mean of its divisors is an integer number (13301574).

Almost surely, 2^51997019 is an apocalyptic number.

51997019 is a deficient number, since it is larger than the sum of its proper divisors (1209277).

51997019 is a wasteful number, since it uses less digits than its factorization.

51997019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1209276.

The product of its (nonzero) digits is 25515, while the sum is 41.

The square root of 51997019 is about 7210.8958528050. The cubic root of 51997019 is about 373.2439830994.

The spelling of 51997019 in words is "fifty-one million, nine hundred ninety-seven thousand, nineteen".