1621813671 has 60 divisors (see below), whose sum is σ = 2550164056. Its totient is φ = 1026587520.

The previous prime is 1621813657. The next prime is 1621813679. The reversal of 1621813671 is 1763181261.

It is not a de Polignac number, because 1621813671 - 2²⁶ = 1554704807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621813679) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 5854785 + ... + 5855061.

Almost surely, 2^1621813671 is an apocalyptic number.

1621813671 is a deficient number, since it is larger than the sum of its proper divisors (928350385).

1621813671 is an equidigital number, since it uses as much as digits as its factorization.

1621813671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414 (or 364 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 1621813671 is about 40271.7478016537. The cubic root of 1621813671 is about 1174.8984178969.

The spelling of 1621813671 in words is "one billion, six hundred twenty-one million, eight hundred thirteen thousand, six hundred seventy-one".