1661151156 has 72 divisors (see below), whose sum is σ = 4518876096. Its totient is φ = 473558400.

The previous prime is 1661151119. The next prime is 1661151157. The reversal of 1661151156 is 6511511661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661151157) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 283456 + ... + 289256.

It is an arithmetic number, because the mean of its divisors is an integer number (62762168).

Almost surely, 2^1661151156 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661151156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2259438048).

1661151156 is an abundant number, since it is smaller than the sum of its proper divisors (2857724940).

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

1661151156 is a wasteful number, since it uses less digits than its factorization.

1661151156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6309 (or 6300 counting only the distinct ones).

The product of its digits is 5400, while the sum is 33.

The square root of 1661151156 is about 40757.2221330159. Note that the first 3 decimals coincide. The cubic root of 1661151156 is about 1184.3217839244.

The spelling of 1661151156 in words is "one billion, six hundred sixty-one million, one hundred fifty-one thousand, one hundred fifty-six".