51651551 has 4 divisors (see below), whose sum is σ = 59030352. Its totient is φ = 44272752.

The previous prime is 51651541. The next prime is 51651553. The reversal of 51651551 is 15515615.

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-51651551 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 (51651553) 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, 3689390 + ... + 3689403.

It is an arithmetic number, because the mean of its divisors is an integer number (14757588).

Almost surely, 2^51651551 is an apocalyptic number.

51651551 is a deficient number, since it is larger than the sum of its proper divisors (7378801).

51651551 is an equidigital number, since it uses as much as digits as its factorization.

51651551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7378800.

The product of its digits is 3750, while the sum is 29.

The square root of 51651551 is about 7186.9013489820. The cubic root of 51651551 is about 372.4155351032.

The spelling of 51651551 in words is "fifty-one million, six hundred fifty-one thousand, five hundred fifty-one".