18690451920 has 360 divisors, whose sum is σ = 74505659904. Its totient is φ = 4271263488.

The previous prime is 18690451919. The next prime is 18690451979. The reversal of 18690451920 is 2915409681.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3671617 + ... + 3676703.

Almost surely, 2^18690451920 is an apocalyptic number.

18690451920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18690451920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37252829952).

18690451920 is an abundant number, since it is smaller than the sum of its proper divisors (55815207984).

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

18690451920 is an frugal number, since it uses more digits than its factorization.

18690451920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5131 (or 5104 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The spelling of 18690451920 in words is "eighteen billion, six hundred ninety million, four hundred fifty-one thousand, nine hundred twenty".