51497749 has 4 divisors (see below), whose sum is σ = 51722860. Its totient is φ = 51272640.

The previous prime is 51497729. The next prime is 51497783. The reversal of 51497749 is 94779415.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94779415 = 5 ⋅18955883.

It can be written as a sum of positive squares in 2 ways, for example, as 31979025 + 19518724 = 5655^2 + 4418^2 .

It is a cyclic number.

It is not a de Polignac number, because 51497749 - 2¹⁷ = 51366677 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51497699 and 51497708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51497729) 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, 112212 + ... + 112669.

It is an arithmetic number, because the mean of its divisors is an integer number (12930715).

Almost surely, 2^51497749 is an apocalyptic number.

It is an amenable number.

51497749 is a deficient number, since it is larger than the sum of its proper divisors (225111).

51497749 is a wasteful number, since it uses less digits than its factorization.

51497749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225110.

The product of its digits is 317520, while the sum is 46.

The square root of 51497749 is about 7176.1932108883. The cubic root of 51497749 is about 372.0455223322.

The spelling of 51497749 in words is "fifty-one million, four hundred ninety-seven thousand, seven hundred forty-nine".