420193987 has 4 divisors (see below), whose sum is σ = 442309480. Its totient is φ = 398078496.

The previous prime is 420193973. The next prime is 420193993. The reversal of 420193987 is 789391024.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 420193987 - 2⁷ = 420193859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (420193927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11057718 + ... + 11057755.

It is an arithmetic number, because the mean of its divisors is an integer number (110577370).

Almost surely, 2^420193987 is an apocalyptic number.

420193987 is a deficient number, since it is larger than the sum of its proper divisors (22115493).

420193987 is a wasteful number, since it uses less digits than its factorization.

420193987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22115492.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 420193987 is about 20498.6337837428. The cubic root of 420193987 is about 749.0025181094.

The spelling of 420193987 in words is "four hundred twenty million, one hundred ninety-three thousand, nine hundred eighty-seven".