1621772828 has 12 divisors (see below), whose sum is σ = 3056418120. Its totient is φ = 748510512.

The previous prime is 1621772827. The next prime is 1621772833. The reversal of 1621772828 is 8282771261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621772827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15593918 + ... + 15594021.

It is an arithmetic number, because the mean of its divisors is an integer number (254701510).

Almost surely, 2^1621772828 is an apocalyptic number.

It is an amenable number.

1621772828 is a deficient number, since it is larger than the sum of its proper divisors (1434645292).

1621772828 is a wasteful number, since it uses less digits than its factorization.

1621772828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31187956 (or 31187954 counting only the distinct ones).

The product of its digits is 150528, while the sum is 44.

The square root of 1621772828 is about 40271.2407059927. The cubic root of 1621772828 is about 1174.8885551160. Note that the first 3 decimals are identical.

The spelling of 1621772828 in words is "one billion, six hundred twenty-one million, seven hundred seventy-two thousand, eight hundred twenty-eight".