51402947 has 4 divisors (see below), whose sum is σ = 51555816. Its totient is φ = 51250080.

The previous prime is 51402881. The next prime is 51402973. The reversal of 51402947 is 74920415.

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: 74920415 = 5 ⋅14984083.

It is a cyclic number.

It is not a de Polignac number, because 51402947 - 2⁸ = 51402691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51402977) 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, 75929 + ... + 76602.

It is an arithmetic number, because the mean of its divisors is an integer number (12888954).

Almost surely, 2^51402947 is an apocalyptic number.

51402947 is a deficient number, since it is larger than the sum of its proper divisors (152869).

51402947 is a wasteful number, since it uses less digits than its factorization.

51402947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152868.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 51402947 is about 7169.5848554850. The cubic root of 51402947 is about 371.8170830595.

The spelling of 51402947 in words is "fifty-one million, four hundred two thousand, nine hundred forty-seven".