1621559459712 has 128 divisors (see below), whose sum is σ = 4389995193120. Its totient is φ = 530145075200.

The previous prime is 1621559459671. The next prime is 1621559459713. The reversal of 1621559459712 is 2179549551261.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×1621559459712² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621559459713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70426762 + ... + 70449782.

Almost surely, 2^{1621559459712} is an apocalyptic number.

1621559459712 is a gapful number since it is divisible by the number (12) 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 1621559459712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2194997596560).

1621559459712 is an abundant number, since it is smaller than the sum of its proper divisors (2768435733408).

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

1621559459712 is a wasteful number, since it uses less digits than its factorization.

1621559459712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26552 (or 26540 counting only the distinct ones).

The product of its digits is 6804000, while the sum is 57.

The spelling of 1621559459712 in words is "one trillion, six hundred twenty-one billion, five hundred fifty-nine million, four hundred fifty-nine thousand, seven hundred twelve".