19901619420 has 24 divisors (see below), whose sum is σ = 55724534544. Its totient is φ = 5307098496.

The previous prime is 19901619371. The next prime is 19901619461. The reversal of 19901619420 is 2491610991.

It is a happy number.

It is a super-2 number, since 2×19901619420² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165846769 + ... + 165846888.

It is an arithmetic number, because the mean of its divisors is an integer number (2321855606).

Almost surely, 2^19901619420 is an apocalyptic number.

19901619420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19901619420 is an abundant number, since it is smaller than the sum of its proper divisors (35822915124).

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

19901619420 is a wasteful number, since it uses less digits than its factorization.

19901619420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331693669 (or 331693667 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 42.

The spelling of 19901619420 in words is "nineteen billion, nine hundred one million, six hundred nineteen thousand, four hundred twenty".