1620651402 has 40 divisors (see below), whose sum is σ = 3633884100. Its totient is φ = 539856576.

The previous prime is 1620651377. The next prime is 1620651421. The reversal of 1620651402 is 2041560261.

1620651402 is a `hidden beast` number, since 1 + 6 + 2 + 0 + 651 + 4 + 0 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1188801441 + 431849961 = 34479^2 + 20781^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 365374 + ... + 369782.

Almost surely, 2^1620651402 is an apocalyptic number.

1620651402 is an abundant number, since it is smaller than the sum of its proper divisors (2013232698).

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

1620651402 is a wasteful number, since it uses less digits than its factorization.

1620651402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6692 (or 6683 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 1620651402 is about 40257.3148881045. The cubic root of 1620651402 is about 1174.6176880841.

The spelling of 1620651402 in words is "one billion, six hundred twenty million, six hundred fifty-one thousand, four hundred two".