421757393820 has 192 divisors, whose sum is σ = 1475111264256. Its totient is φ = 87804149760.

The previous prime is 421757393819. The next prime is 421757393879. The reversal of 421757393820 is 28393757124.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 731397 + ... + 1174076.

It is an arithmetic number, because the mean of its divisors is an integer number (7682871168).

Almost surely, 2^421757393820 is an apocalyptic number.

It is an amenable number.

421757393820 is an abundant number, since it is smaller than the sum of its proper divisors (1053353870436).

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

421757393820 is a wasteful number, since it uses less digits than its factorization.

421757393820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1905540 (or 1905538 counting only the distinct ones).

The product of its (nonzero) digits is 2540160, while the sum is 51.

The spelling of 421757393820 in words is "four hundred twenty-one billion, seven hundred fifty-seven million, three hundred ninety-three thousand, eight hundred twenty".