1864721401 has 4 divisors (see below), whose sum is σ = 1864920400. Its totient is φ = 1864522404.

The previous prime is 1864721399. The next prime is 1864721413. The reversal of 1864721401 is 1041274681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1041274681 = 30181 ⋅34501.

It is a cyclic number.

It is not a de Polignac number, because 1864721401 - 2¹ = 1864721399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1864721471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84711 + ... + 104428.

It is an arithmetic number, because the mean of its divisors is an integer number (466230100).

Almost surely, 2^1864721401 is an apocalyptic number.

It is an amenable number.

1864721401 is a deficient number, since it is larger than the sum of its proper divisors (198999).

1864721401 is an equidigital number, since it uses as much as digits as its factorization.

1864721401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198998.

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 1864721401 is about 43182.4200456621. The cubic root of 1864721401 is about 1230.8486445149.

The spelling of 1864721401 in words is "one billion, eight hundred sixty-four million, seven hundred twenty-one thousand, four hundred one".