51243961 has 4 divisors (see below), whose sum is σ = 52897024. Its totient is φ = 49590900.

The previous prime is 51243953. The next prime is 51243979. The reversal of 51243961 is 16934215.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51243961 - 2³ = 51243953 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 1653031 = 51243961 / (5 + 1 + 2 + 4 + 3 + 9 + 6 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51243911) 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, 826485 + ... + 826546.

It is an arithmetic number, because the mean of its divisors is an integer number (13224256).

Almost surely, 2^51243961 is an apocalyptic number.

It is an amenable number.

51243961 is a deficient number, since it is larger than the sum of its proper divisors (1653063).

51243961 is a wasteful number, since it uses less digits than its factorization.

51243961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1653062.

The product of its digits is 6480, while the sum is 31.

The square root of 51243961 is about 7158.4887371567. The cubic root of 51243961 is about 371.4333517488.

The spelling of 51243961 in words is "fifty-one million, two hundred forty-three thousand, nine hundred sixty-one".