1661667722 has 64 divisors (see below), whose sum is σ = 2983115520. Its totient is φ = 684288000.

The previous prime is 1661667677. The next prime is 1661667727. The reversal of 1661667722 is 2277661661.

It is a super-2 number, since 2×1661667722² = 5522279236673338568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1661667727) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4707098 + ... + 4707450.

It is an arithmetic number, because the mean of its divisors is an integer number (46611180).

Almost surely, 2^1661667722 is an apocalyptic number.

1661667722 is a deficient number, since it is larger than the sum of its proper divisors (1321447798).

1661667722 is a wasteful number, since it uses less digits than its factorization.

1661667722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639.

The product of its digits is 254016, while the sum is 44.

The square root of 1661667722 is about 40763.5587504330. The cubic root of 1661667722 is about 1184.4445335330. Note that the first 3 decimals are identical.

The spelling of 1661667722 in words is "one billion, six hundred sixty-one million, six hundred sixty-seven thousand, seven hundred twenty-two".