1661826620 has 24 divisors (see below), whose sum is σ = 3534014400. Its totient is φ = 656315712.

The previous prime is 1661826589. The next prime is 1661826667. The reversal of 1661826620 is 266281661.

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, 524315 + ... + 527474.

It is an arithmetic number, because the mean of its divisors is an integer number (147250600).

Almost surely, 2^1661826620 is an apocalyptic number.

1661826620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661826620 is an abundant number, since it is smaller than the sum of its proper divisors (1872187780).

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

1661826620 is a wasteful number, since it uses less digits than its factorization.

1661826620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1051877 (or 1051875 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 1661826620 is about 40765.5077240551. The cubic root of 1661826620 is about 1184.4822867424.

The spelling of 1661826620 in words is "one billion, six hundred sixty-one million, eight hundred twenty-six thousand, six hundred twenty".