51144252621 has 32 divisors (see below), whose sum is σ = 85170244608. Its totient is φ = 26521184640.

The previous prime is 51144252617. The next prime is 51144252659. The reversal of 51144252621 is 12625244115.

It is a happy number.

It is not a de Polignac number, because 51144252621 - 2² = 51144252617 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51144252661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66576 + ... + 326681.

It is an arithmetic number, because the mean of its divisors is an integer number (2661570144).

Almost surely, 2^51144252621 is an apocalyptic number.

It is an amenable number.

51144252621 is a deficient number, since it is larger than the sum of its proper divisors (34025991987).

51144252621 is a wasteful number, since it uses less digits than its factorization.

51144252621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393841.

The product of its digits is 19200, while the sum is 33.

Adding to 51144252621 its reverse (12625244115), we get a palindrome (63769496736).

The spelling of 51144252621 in words is "fifty-one billion, one hundred forty-four million, two hundred fifty-two thousand, six hundred twenty-one".