1566117990 has 56 divisors (see below), whose sum is σ = 4226604768. Its totient is φ = 417629520.

The previous prime is 1566117989. The next prime is 1566118009. The reversal of 1566117990 is 997116651.

1566117990 is a `hidden beast` number, since 1 + 566 + 11 + 79 + 9 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 100126 + ... + 114705.

Almost surely, 2^1566117990 is an apocalyptic number.

1566117990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1566117990 is an abundant number, since it is smaller than the sum of its proper divisors (2660486778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1566117990 is an equidigital number, since it uses as much as digits as its factorization.

1566117990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214856 (or 214841 counting only the distinct ones).

The product of its (nonzero) digits is 102060, while the sum is 45.

The square root of 1566117990 is about 39574.2086465415. The cubic root of 1566117990 is about 1161.2921565092.

The spelling of 1566117990 in words is "one billion, five hundred sixty-six million, one hundred seventeen thousand, nine hundred ninety".