1661722770 has 16 divisors (see below), whose sum is σ = 3988134720. Its totient is φ = 443126064.

The previous prime is 1661722763. The next prime is 1661722781. The reversal of 1661722770 is 772271661.

It is a super-2 number, since 2×1661722770² = 5522645128672945800, which contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 27695350 + ... + 27695409.

It is an arithmetic number, because the mean of its divisors is an integer number (249258420).

Almost surely, 2^1661722770 is an apocalyptic number.

1661722770 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1661722770 is an abundant number, since it is smaller than the sum of its proper divisors (2326411950).

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

1661722770 is a wasteful number, since it uses less digits than its factorization.

1661722770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55390769.

The product of its (nonzero) digits is 49392, while the sum is 39.

The square root of 1661722770 is about 40764.2339557608. The cubic root of 1661722770 is about 1184.4576128793.

The spelling of 1661722770 in words is "one billion, six hundred sixty-one million, seven hundred twenty-two thousand, seven hundred seventy".