51781169 has 12 divisors (see below), whose sum is σ = 57743088. Its totient is φ = 46050600.

The previous prime is 51781157. The next prime is 51781181. The reversal of 51781169 is 96118715.

It is an interprime number because it is at equal distance from previous prime (51781157) and next prime (51781181).

It is not a de Polignac number, because 51781169 - 2¹⁶ = 51715633 is a prime.

It is a super-2 number, since 2×51781169² = 5362578926013122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51781109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23234 + ... + 25364.

It is an arithmetic number, because the mean of its divisors is an integer number (4811924).

Almost surely, 2^51781169 is an apocalyptic number.

It is an amenable number.

51781169 is a deficient number, since it is larger than the sum of its proper divisors (5961919).

51781169 is a wasteful number, since it uses less digits than its factorization.

51781169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2236 (or 2189 counting only the distinct ones).

The product of its digits is 15120, while the sum is 38.

The square root of 51781169 is about 7195.9133541198. The cubic root of 51781169 is about 372.7267967095.

The spelling of 51781169 in words is "fifty-one million, seven hundred eighty-one thousand, one hundred sixty-nine".