1621366664740 has 24 divisors (see below), whose sum is σ = 3406682139840. Its totient is φ = 648201495648.

The previous prime is 1621366664689. The next prime is 1621366664741. The reversal of 1621366664740 is 474666631261.

It is a super-2 number, since 2×1621366664740² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1621366664741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21534622 + ... + 21609781.

It is an arithmetic number, because the mean of its divisors is an integer number (141945089160).

Almost surely, 2^{1621366664740} is an apocalyptic number.

1621366664740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621366664740 is an abundant number, since it is smaller than the sum of its proper divisors (1785315475100).

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

1621366664740 is a wasteful number, since it uses less digits than its factorization.

1621366664740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43146291 (or 43146289 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 52.

The spelling of 1621366664740 in words is "one trillion, six hundred twenty-one billion, three hundred sixty-six million, six hundred sixty-four thousand, seven hundred forty".