51403687421 has 4 divisors (see below), whose sum is σ = 51744109344. Its totient is φ = 51063265500.

The previous prime is 51403687417. The next prime is 51403687471. The reversal of 51403687421 is 12478630415.

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 51403687421 - 2² = 51403687417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51403687471) 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, 170210735 + ... + 170211036.

It is an arithmetic number, because the mean of its divisors is an integer number (12936027336).

Almost surely, 2^51403687421 is an apocalyptic number.

It is an amenable number.

51403687421 is a deficient number, since it is larger than the sum of its proper divisors (340421923).

51403687421 is a wasteful number, since it uses less digits than its factorization.

51403687421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340421922.

The product of its (nonzero) digits is 161280, while the sum is 41.

The spelling of 51403687421 in words is "fifty-one billion, four hundred three million, six hundred eighty-seven thousand, four hundred twenty-one".