1656620646 has 16 divisors (see below), whose sum is σ = 3316857600. Its totient is φ = 551604168.

The previous prime is 1656620633. The next prime is 1656620653. The reversal of 1656620646 is 6460266561.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1656620598 and 1656620607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144706 + ... + 155733.

It is an arithmetic number, because the mean of its divisors is an integer number (207303600).

Almost surely, 2^1656620646 is an apocalyptic number.

1656620646 is an abundant number, since it is smaller than the sum of its proper divisors (1660236954).

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

1656620646 is a wasteful number, since it uses less digits than its factorization.

1656620646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301363.

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 1656620646 is about 40701.6049560702. The cubic root of 1656620646 is about 1183.2441242189.

The spelling of 1656620646 in words is "one billion, six hundred fifty-six million, six hundred twenty thousand, six hundred forty-six".