1621713668 has 6 divisors (see below), whose sum is σ = 2837998926. Its totient is φ = 810856832.

The previous prime is 1621713649. The next prime is 1621713683. The reversal of 1621713668 is 8663171261.

It can be written as a sum of positive squares in only one way, i.e., 1614271684 + 7441984 = 40178^2 + 2728^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202714205 + ... + 202714212.

It is an arithmetic number, because the mean of its divisors is an integer number (472999821).

Almost surely, 2^1621713668 is an apocalyptic number.

It is an amenable number.

1621713668 is a deficient number, since it is larger than the sum of its proper divisors (1216285258).

1621713668 is a wasteful number, since it uses less digits than its factorization.

1621713668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405428421 (or 405428419 counting only the distinct ones).

The product of its digits is 72576, while the sum is 41.

The square root of 1621713668 is about 40270.5061800817. The cubic root of 1621713668 is about 1174.8742688463.

The spelling of 1621713668 in words is "one billion, six hundred twenty-one million, seven hundred thirteen thousand, six hundred sixty-eight".