1318151896421 has 4 divisors (see below), whose sum is σ = 1318394342892. Its totient is φ = 1317909449952.

The previous prime is 1318151896417. The next prime is 1318151896561. The reversal of 1318151896421 is 1246981518131.

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

It can be written as a sum of positive squares in 2 ways, for example, as 245713533025 + 1072438363396 = 495695^2 + 1035586^2 .

It is a cyclic number.

It is not a de Polignac number, because 1318151896421 - 2² = 1318151896417 is a prime.

It is a super-3 number, since 3×1318151896421³ (a number of 37 digits) contains 333 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 1318151896421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1318151886421) 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, 121215080 + ... + 121225953.

It is an arithmetic number, because the mean of its divisors is an integer number (329598585723).

Almost surely, 2^{1318151896421} is an apocalyptic number.

It is an amenable number.

1318151896421 is a deficient number, since it is larger than the sum of its proper divisors (242446471).

1318151896421 is an equidigital number, since it uses as much as digits as its factorization.

1318151896421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242446470.

The product of its digits is 414720, while the sum is 50.

The spelling of 1318151896421 in words is "one trillion, three hundred eighteen billion, one hundred fifty-one million, eight hundred ninety-six thousand, four hundred twenty-one".