1320405551 has 8 divisors (see below), whose sum is σ = 1450331520. Its totient is φ = 1196522712.

The previous prime is 1320405503. The next prime is 1320405571. The reversal of 1320405551 is 1555040231.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320405551 is a prime.

It is a super-2 number, since 2×1320405551² = 3486941638223227202, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1320405551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320405571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1510325 + ... + 1511198.

It is an arithmetic number, because the mean of its divisors is an integer number (181291440).

Almost surely, 2^1320405551 is an apocalyptic number.

1320405551 is a deficient number, since it is larger than the sum of its proper divisors (129925969).

1320405551 is a wasteful number, since it uses less digits than its factorization.

1320405551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3021565.

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 1320405551 is about 36337.3850324979. The cubic root of 1320405551 is about 1097.0736408410.

Adding to 1320405551 its reverse (1555040231), we get a palindrome (2875445782).

The spelling of 1320405551 in words is "one billion, three hundred twenty million, four hundred five thousand, five hundred fifty-one".