1561618008 has 32 divisors (see below), whose sum is σ = 4337828400. Its totient is φ = 520539264.

The previous prime is 1561618001. The next prime is 1561618021. The reversal of 1561618008 is 8008161651.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561618001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3614641 + ... + 3615072.

Almost surely, 2^1561618008 is an apocalyptic number.

1561618008 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1561618008 is an abundant number, since it is smaller than the sum of its proper divisors (2776210392).

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

1561618008 is a wasteful number, since it uses less digits than its factorization.

1561618008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7229728 (or 7229718 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 1561618008 is about 39517.3127628891. The cubic root of 1561618008 is about 1160.1788289498.

Adding to 1561618008 its reverse (8008161651), we get a palindrome (9569779659).

The spelling of 1561618008 in words is "one billion, five hundred sixty-one million, six hundred eighteen thousand, eight".