1377641621 has 4 divisors (see below), whose sum is σ = 1379097312. Its totient is φ = 1376185932.

The previous prime is 1377641599. The next prime is 1377641641. The reversal of 1377641621 is 1261467731.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1261467731 = 59 ⋅21380809.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1377641621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1377641641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 726425 + ... + 728318.

It is an arithmetic number, because the mean of its divisors is an integer number (344774328).

Almost surely, 2^1377641621 is an apocalyptic number.

It is an amenable number.

1377641621 is a deficient number, since it is larger than the sum of its proper divisors (1455691).

1377641621 is an equidigital number, since it uses as much as digits as its factorization.

1377641621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1455690.

The product of its digits is 42336, while the sum is 38.

The square root of 1377641621 is about 37116.5949542789. The cubic root of 1377641621 is about 1112.7017003475.

The spelling of 1377641621 in words is "one billion, three hundred seventy-seven million, six hundred forty-one thousand, six hundred twenty-one".