1821016401 has 8 divisors (see below), whose sum is σ = 2511746880. Its totient is φ = 1172148432.

The previous prime is 1821016391. The next prime is 1821016409. The reversal of 1821016401 is 1046101281.

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

It is not a de Polignac number, because 1821016401 - 2¹⁰ = 1821015377 is a prime.

It is a super-2 number, since 2×1821016401² = 6632201465421985602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1821016409) 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, 10465525 + ... + 10465698.

It is an arithmetic number, because the mean of its divisors is an integer number (313968360).

Almost surely, 2^1821016401 is an apocalyptic number.

It is an amenable number.

1821016401 is a deficient number, since it is larger than the sum of its proper divisors (690730479).

1821016401 is a wasteful number, since it uses less digits than its factorization.

1821016401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20931255.

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 1821016401 is about 42673.3687561692. The cubic root of 1821016401 is about 1221.1563883314.

Adding to 1821016401 its reverse (1046101281), we get a palindrome (2867117682).

The spelling of 1821016401 in words is "one billion, eight hundred twenty-one million, sixteen thousand, four hundred one".