1551555205420 has 48 divisors (see below), whose sum is σ = 3763558518048. Its totient is φ = 531013544960.

The previous prime is 1551555205399. The next prime is 1551555205441. The reversal of 1551555205420 is 245025551551.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1551555205399) and next prime (1551555205441).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 207423427 + ... + 207430906.

It is an arithmetic number, because the mean of its divisors is an integer number (78407469126).

Almost surely, 2^{1551555205420} is an apocalyptic number.

1551555205420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1551555205420 is an abundant number, since it is smaller than the sum of its proper divisors (2212003312628).

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

1551555205420 is a wasteful number, since it uses less digits than its factorization.

1551555205420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414854370 (or 414854368 counting only the distinct ones).

The product of its (nonzero) digits is 250000, while the sum is 40.

The spelling of 1551555205420 in words is "one trillion, five hundred fifty-one billion, five hundred fifty-five million, two hundred five thousand, four hundred twenty".