18961290000 has 675 divisors, whose sum is σ = 73145958457. Its totient is φ = 4758912000.

The previous prime is 18961289981. The next prime is 18961290013. The reversal of 18961290000 is 9216981.

The square root of 18961290000 is 137700.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 7 ways, for example, as 9259827984 + 9701462016 = 96228^2 + 98496^2 .

It is a tau number, because it is divible by the number of its divisors (675).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 1115369992 + ... + 1115370008.

Almost surely, 2^18961290000 is an apocalyptic number.

18961290000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18961290000 is the 137700-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18961290000

18961290000 is an abundant number, since it is smaller than the sum of its proper divisors (54184668457).

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

18961290000 is an frugal number, since it uses more digits than its factorization.

18961290000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

Multiplying 18961290000 by its sum of digits (36), we get a square (682606440000 = 826200²).

18961290000 divided by its sum of digits (36) gives a square (526702500 = 22950²).

The spelling of 18961290000 in words is "eighteen billion, nine hundred sixty-one million, two hundred ninety thousand".