1621212261550 has 192 divisors, whose sum is σ = 3729595290624. Its totient is φ = 511711488000.

The previous prime is 1621212261463. The next prime is 1621212261569. The reversal of 1621212261550 is 551622121261.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 49862599 + ... + 49895101.

It is an arithmetic number, because the mean of its divisors is an integer number (19424975472).

Almost surely, 2^{1621212261550} is an apocalyptic number.

1621212261550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1621212261550 is an abundant number, since it is smaller than the sum of its proper divisors (2108383029074).

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

1621212261550 is a wasteful number, since it uses less digits than its factorization.

1621212261550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32723 (or 32718 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 34.

The spelling of 1621212261550 in words is "one trillion, six hundred twenty-one billion, two hundred twelve million, two hundred sixty-one thousand, five hundred fifty".