1620778361454 has 128 divisors (see below), whose sum is σ = 4204797972480. Its totient is φ = 453223618272.

The previous prime is 1620778361443. The next prime is 1620778361599. The reversal of 1620778361454 is 4541638770261.

1620778361454 is a `hidden beast` number, since 1 + 6 + 207 + 78 + 361 + 4 + 5 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 1620778361454.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3115617 + ... + 3598419.

It is an arithmetic number, because the mean of its divisors is an integer number (32849984160).

Almost surely, 2^{1620778361454} is an apocalyptic number.

1620778361454 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1620778361454, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2102398986240).

1620778361454 is an abundant number, since it is smaller than the sum of its proper divisors (2584019611026).

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

1620778361454 is a wasteful number, since it uses less digits than its factorization.

1620778361454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483011 (or 483005 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 54.

The spelling of 1620778361454 in words is "one trillion, six hundred twenty billion, seven hundred seventy-eight million, three hundred sixty-one thousand, four hundred fifty-four".