1621742976 has 192 divisors, whose sum is σ = 5399896320. Its totient is φ = 457583616.

The previous prime is 1621742957. The next prime is 1621742977. The reversal of 1621742976 is 6792471261.

1621742976 is a `hidden beast` number, since 1 + 6 + 217 + 429 + 7 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621742977) 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, 668101 + ... + 670523.

It is an arithmetic number, because the mean of its divisors is an integer number (28124460).

Almost surely, 2^1621742976 is an apocalyptic number.

1621742976 is a gapful number since it is divisible by the number (16) 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 1621742976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2699948160).

1621742976 is an abundant number, since it is smaller than the sum of its proper divisors (3778153344).

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

1621742976 is a wasteful number, since it uses less digits than its factorization.

1621742976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2533 (or 2518 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 1621742976 is about 40270.8700675811. The cubic root of 1621742976 is about 1174.8813463406.

The spelling of 1621742976 in words is "one billion, six hundred twenty-one million, seven hundred forty-two thousand, nine hundred seventy-six".