1621836401 has 8 divisors (see below), whose sum is σ = 1645712640. Its totient is φ = 1598005152.

The previous prime is 1621836373. The next prime is 1621836443. The reversal of 1621836401 is 1046381261.

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

It is a cyclic number.

It is not a de Polignac number, because 1621836401 - 2¹⁴ = 1621820017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621836001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65156 + ... + 86538.

It is an arithmetic number, because the mean of its divisors is an integer number (205714080).

Almost surely, 2^1621836401 is an apocalyptic number.

It is an amenable number.

1621836401 is a deficient number, since it is larger than the sum of its proper divisors (23876239).

1621836401 is a wasteful number, since it uses less digits than its factorization.

1621836401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22495.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1621836401 is about 40272.0300084314. The cubic root of 1621836401 is about 1174.9039066730.

The spelling of 1621836401 in words is "one billion, six hundred twenty-one million, eight hundred thirty-six thousand, four hundred one".