6421897550 has 12 divisors (see below), whose sum is σ = 11944729536. Its totient is φ = 2568759000.

The previous prime is 6421897529. The next prime is 6421897553. The reversal of 6421897550 is 557981246.

It is a happy number.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 6421897495 and 6421897504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6421897553) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 64218926 + ... + 64219025.

It is an arithmetic number, because the mean of its divisors is an integer number (995394128).

Almost surely, 2^6421897550 is an apocalyptic number.

6421897550 is a deficient number, since it is larger than the sum of its proper divisors (5522831986).

6421897550 is a wasteful number, since it uses less digits than its factorization.

6421897550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128437963 (or 128437958 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 47.

The square root of 6421897550 is about 80136.7428212552. The cubic root of 6421897550 is about 1858.7506110265.

The spelling of 6421897550 in words is "six billion, four hundred twenty-one million, eight hundred ninety-seven thousand, five hundred fifty".