1661406377 has 8 divisors (see below), whose sum is σ = 1678582464. Its totient is φ = 1644250608.

The previous prime is 1661406323. The next prime is 1661406391. The reversal of 1661406377 is 7736041661.

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

It is a cyclic number.

It is not a de Polignac number, because 1661406377 - 2⁸ = 1661406121 is a prime.

It is a super-2 number, since 2×1661406377² = 5520542299072532258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1661406077) 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 7 ways as a sum of consecutive naturals, for example, 202283 + ... + 210335.

It is an arithmetic number, because the mean of its divisors is an integer number (209822808).

Almost surely, 2^1661406377 is an apocalyptic number.

It is an amenable number.

1661406377 is a deficient number, since it is larger than the sum of its proper divisors (17176087).

1661406377 is a wasteful number, since it uses less digits than its factorization.

1661406377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10159.

The product of its (nonzero) digits is 127008, while the sum is 41.

The square root of 1661406377 is about 40760.3530038688. The cubic root of 1661406377 is about 1184.3824342973.

The spelling of 1661406377 in words is "one billion, six hundred sixty-one million, four hundred six thousand, three hundred seventy-seven".