1621177445 has 4 divisors (see below), whose sum is σ = 1945412940. Its totient is φ = 1296941952.

The previous prime is 1621177423. The next prime is 1621177483. The reversal of 1621177445 is 5447711261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5447711261 = 3041 ⋅1791421.

It can be written as a sum of positive squares in 2 ways, for example, as 257057089 + 1364120356 = 16033^2 + 36934^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621177445 - 2⁶ = 1621177381 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1621177399 and 1621177408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 162117740 + ... + 162117749.

It is an arithmetic number, because the mean of its divisors is an integer number (486353235).

Almost surely, 2^1621177445 is an apocalyptic number.

It is an amenable number.

1621177445 is a deficient number, since it is larger than the sum of its proper divisors (324235495).

1621177445 is an equidigital number, since it uses as much as digits as its factorization.

1621177445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324235494.

The product of its digits is 47040, while the sum is 38.

The square root of 1621177445 is about 40263.8478662932. The cubic root of 1621177445 is about 1174.7447630306.

The spelling of 1621177445 in words is "one billion, six hundred twenty-one million, one hundred seventy-seven thousand, four hundred forty-five".