1621157665049 has 8 divisors (see below), whose sum is σ = 1746146946432. Its totient is φ = 1496209075920.

The previous prime is 1621157665037. The next prime is 1621157665093. The reversal of 1621157665049 is 9405667511261.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1621157665049 - 2⁸ = 1621157664793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621157665549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10090289 + ... + 10249694.

It is an arithmetic number, because the mean of its divisors is an integer number (218268368304).

Almost surely, 2^{1621157665049} is an apocalyptic number.

It is an amenable number.

1621157665049 is a deficient number, since it is larger than the sum of its proper divisors (124989281383).

1621157665049 is a wasteful number, since it uses less digits than its factorization.

1621157665049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20346127.

The product of its (nonzero) digits is 2721600, while the sum is 53.

The spelling of 1621157665049 in words is "one trillion, six hundred twenty-one billion, one hundred fifty-seven million, six hundred sixty-five thousand, forty-nine".