16377561 has 6 divisors (see below), whose sum is σ = 23656490. Its totient is φ = 10918368.

The previous prime is 16377503. The next prime is 16377589. The reversal of 16377561 is 16577361.

It can be written as a sum of positive squares in only one way, i.e., 8643600 + 7733961 = 2940^2 + 2781^2 .

It is not a de Polignac number, because 16377561 - 2⁶ = 16377497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16377461) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 909856 + ... + 909873.

Almost surely, 2^16377561 is an apocalyptic number.

It is an amenable number.

16377561 is a deficient number, since it is larger than the sum of its proper divisors (7278929).

16377561 is a wasteful number, since it uses less digits than its factorization.

16377561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1819735 (or 1819732 counting only the distinct ones).

The product of its digits is 26460, while the sum is 36.

The square root of 16377561 is about 4046.9199399049. The cubic root of 16377561 is about 253.9508915744.

The spelling of 16377561 in words is "sixteen million, three hundred seventy-seven thousand, five hundred sixty-one".