1621769499 has 16 divisors (see below), whose sum is σ = 2745853440. Its totient is φ = 926725320.

The previous prime is 1621769497. The next prime is 1621769503. The reversal of 1621769499 is 9949671261.

It is a happy number.

1621769499 is a `hidden beast` number, since 1 + 621 + 7 + 6 + 9 + 4 + 9 + 9 = 666.

It is not a de Polignac number, because 1621769499 - 2¹ = 1621769497 is a prime.

It is a super-2 number, since 2×1621769499² = 5260272615773422002, which contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1621769497) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4290207 + ... + 4290584.

It is an arithmetic number, because the mean of its divisors is an integer number (171615840).

Almost surely, 2^1621769499 is an apocalyptic number.

1621769499 is a deficient number, since it is larger than the sum of its proper divisors (1124083941).

1621769499 is an equidigital number, since it uses as much as digits as its factorization.

1621769499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8580807 (or 8580801 counting only the distinct ones).

The product of its digits is 1469664, while the sum is 54.

The square root of 1621769499 is about 40271.1993737460. The cubic root of 1621769499 is about 1174.8877512207.

The spelling of 1621769499 in words is "one billion, six hundred twenty-one million, seven hundred sixty-nine thousand, four hundred ninety-nine".