1620401008 has 20 divisors (see below), whose sum is σ = 3140183440. Its totient is φ = 810031104.

The previous prime is 1620400981. The next prime is 1620401033. The reversal of 1620401008 is 8001040261.

It is a self number, because there is not a number n which added to its sum of digits gives 1620401008.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109813 + ... + 123691.

It is an arithmetic number, because the mean of its divisors is an integer number (157009172).

Almost surely, 2^1620401008 is an apocalyptic number.

It is an amenable number.

1620401008 is a deficient number, since it is larger than the sum of its proper divisors (1519782432).

1620401008 is a wasteful number, since it uses less digits than its factorization.

1620401008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21184 (or 21178 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 1620401008 is about 40254.2048486863. The cubic root of 1620401008 is about 1174.5571913461.

Adding to 1620401008 its reverse (8001040261), we get a palindrome (9621441269).

The spelling of 1620401008 in words is "one billion, six hundred twenty million, four hundred one thousand, eight".