51990451 has 4 divisors (see below), whose sum is σ = 52005904. Its totient is φ = 51975000.

The previous prime is 51990431. The next prime is 51990461. The reversal of 51990451 is 15409915.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51990451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51990401) 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, 300 + ... + 10201.

It is an arithmetic number, because the mean of its divisors is an integer number (13001476).

Almost surely, 2^51990451 is an apocalyptic number.

51990451 is a deficient number, since it is larger than the sum of its proper divisors (15453).

51990451 is a wasteful number, since it uses less digits than its factorization.

51990451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15452.

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 51990451 is about 7210.4404165072. The cubic root of 51990451 is about 373.2282670080.

It can be divided in two parts, 51990 and 451, that added together give a square (52441 = 229²).

The spelling of 51990451 in words is "fifty-one million, nine hundred ninety thousand, four hundred fifty-one".