51011399 has 4 divisors (see below), whose sum is σ = 52656960. Its totient is φ = 49365840.

The previous prime is 51011383. The next prime is 51011413. The reversal of 51011399 is 99311015.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99311015 = 5 ⋅19862203.

It is a cyclic number.

It is not a de Polignac number, because 51011399 - 2⁴ = 51011383 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 (51011699) 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, 822734 + ... + 822795.

It is an arithmetic number, because the mean of its divisors is an integer number (13164240).

Almost surely, 2^51011399 is an apocalyptic number.

51011399 is a deficient number, since it is larger than the sum of its proper divisors (1645561).

51011399 is a wasteful number, since it uses less digits than its factorization.

51011399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1645560.

The product of its (nonzero) digits is 1215, while the sum is 29.

The square root of 51011399 is about 7142.2264735865. The cubic root of 51011399 is about 370.8706038821.

The spelling of 51011399 in words is "fifty-one million, eleven thousand, three hundred ninety-nine".