1666747401 has 16 divisors (see below), whose sum is σ = 2445819840. Its totient is φ = 1001208320.

The previous prime is 1666747387. The next prime is 1666747427. The reversal of 1666747401 is 1047476661.

It is a cyclic number.

It is not a de Polignac number, because 1666747401 - 2¹³ = 1666739209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666747001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 219756 + ... + 227213.

It is an arithmetic number, because the mean of its divisors is an integer number (152863740).

Almost surely, 2^1666747401 is an apocalyptic number.

1666747401 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1666747401 is a deficient number, since it is larger than the sum of its proper divisors (779072439).

1666747401 is a wasteful number, since it uses less digits than its factorization.

1666747401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447096.

The product of its (nonzero) digits is 169344, while the sum is 42.

The square root of 1666747401 is about 40825.8178240192. The cubic root of 1666747401 is about 1185.6502454149.

The spelling of 1666747401 in words is "one billion, six hundred sixty-six million, seven hundred forty-seven thousand, four hundred one".