1621974164 has 12 divisors (see below), whose sum is σ = 2848144404. Its totient is φ = 808218624.

The previous prime is 1621974073. The next prime is 1621974209. The reversal of 1621974164 is 4614791261.

It can be written as a sum of positive squares in 2 ways, for example, as 1588819600 + 33154564 = 39860^2 + 5758^2 .

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, 690797 + ... + 693140.

It is an arithmetic number, because the mean of its divisors is an integer number (237345367).

Almost surely, 2^1621974164 is an apocalyptic number.

It is an amenable number.

1621974164 is a deficient number, since it is larger than the sum of its proper divisors (1226170240).

1621974164 is a wasteful number, since it uses less digits than its factorization.

1621974164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1384234 (or 1384232 counting only the distinct ones).

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

The square root of 1621974164 is about 40273.7403775711. The cubic root of 1621974164 is about 1174.9371721952.

The spelling of 1621974164 in words is "one billion, six hundred twenty-one million, nine hundred seventy-four thousand, one hundred sixty-four".