1621220838 has 8 divisors (see below), whose sum is σ = 3242441688. Its totient is φ = 540406944.

The previous prime is 1621220743. The next prime is 1621220863. The reversal of 1621220838 is 8380221261.

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

1621220838 is an admirable number.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1621220799 and 1621220808.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 135101731 + ... + 135101742.

It is an arithmetic number, because the mean of its divisors is an integer number (405305211).

Almost surely, 2^1621220838 is an apocalyptic number.

1621220838 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1621220838 is a wasteful number, since it uses less digits than its factorization.

1621220838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270203478.

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 1621220838 is about 40264.3867207735. The cubic root of 1621220838 is about 1174.7552441462.

The spelling of 1621220838 in words is "one billion, six hundred twenty-one million, two hundred twenty thousand, eight hundred thirty-eight".