1621031099 has 18 divisors (see below), whose sum is σ = 1719792396. Its totient is φ = 1527806280.

The previous prime is 1621031089. The next prime is 1621031101. The reversal of 1621031099 is 9901301261.

It is not a de Polignac number, because 1621031099 - 2⁸ = 1621030843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1621031059) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3301244 + ... + 3301734.

It is an arithmetic number, because the mean of its divisors is an integer number (95544022).

Almost surely, 2^1621031099 is an apocalyptic number.

1621031099 is a deficient number, since it is larger than the sum of its proper divisors (98761297).

1621031099 is an frugal number, since it uses more digits than its factorization.

1621031099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 695 (or 593 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 1621031099 is about 40262.0304877933. The cubic root of 1621031099 is about 1174.7094133385.

The spelling of 1621031099 in words is "one billion, six hundred twenty-one million, thirty-one thousand, ninety-nine".