1867121798401 has 4 divisors (see below), whose sum is σ = 1892698809412. Its totient is φ = 1841544787392.

The previous prime is 1867121798393. The next prime is 1867121798431. The reversal of 1867121798401 is 1048971217681.

It is a happy number.

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 1118898528400 + 748223270001 = 1057780^2 + 864999^2 .

It is a cyclic number.

It is not a de Polignac number, because 1867121798401 - 2³ = 1867121798393 is a prime.

It is a super-2 number, since 2×1867121798401² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1867121798431) 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, 12788505396 + ... + 12788505541.

It is an arithmetic number, because the mean of its divisors is an integer number (473174702353).

Almost surely, 2^{1867121798401} is an apocalyptic number.

It is an amenable number.

1867121798401 is a deficient number, since it is larger than the sum of its proper divisors (25577011011).

1867121798401 is an equidigital number, since it uses as much as digits as its factorization.

1867121798401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25577011010.

The product of its (nonzero) digits is 1354752, while the sum is 55.

The spelling of 1867121798401 in words is "one trillion, eight hundred sixty-seven billion, one hundred twenty-one million, seven hundred ninety-eight thousand, four hundred one".