1621992968 has 36 divisors (see below), whose sum is σ = 3156151245. Its totient is φ = 781436320.

The previous prime is 1621992961. The next prime is 1621992971. The reversal of 1621992968 is 8692991261.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 1621028644 + 964324 = 40262^2 + 982^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=28478.

It is a super-2 number, since 2×1621992968² = 5261722376482898048, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621992961) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3303203 + ... + 3303693.

Almost surely, 2^1621992968 is an apocalyptic number.

It is an amenable number.

1621992968 is a deficient number, since it is larger than the sum of its proper divisors (1534158277).

1621992968 is an frugal number, since it uses more digits than its factorization.

1621992968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1046 (or 522 counting only the distinct ones).

The product of its digits is 839808, while the sum is 53.

The square root of 1621992968 is about 40273.9738292610. The cubic root of 1621992968 is about 1174.9417126360.

The spelling of 1621992968 in words is "one billion, six hundred twenty-one million, nine hundred ninety-two thousand, nine hundred sixty-eight".