987907421 has 4 divisors (see below), whose sum is σ = 988133532. Its totient is φ = 987681312.

The previous prime is 987907409. The next prime is 987907433. The reversal of 987907421 is 124709789.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 124709789 = 941 ⋅132529.

It is an interprime number because it is at equal distance from previous prime (987907409) and next prime (987907433).

It can be written as a sum of positive squares in 2 ways, for example, as 352312900 + 635594521 = 18770^2 + 25211^2 .

It is a cyclic number.

It is not a de Polignac number, because 987907421 - 2⁶ = 987907357 is a prime.

It is a super-2 number, since 2×987907421² = 1951922144933742482, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987907471) 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, 106370 + ... + 115283.

It is an arithmetic number, because the mean of its divisors is an integer number (247033383).

Almost surely, 2^987907421 is an apocalyptic number.

It is an amenable number.

987907421 is a deficient number, since it is larger than the sum of its proper divisors (226111).

987907421 is a wasteful number, since it uses less digits than its factorization.

987907421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226110.

The product of its (nonzero) digits is 254016, while the sum is 47.

The square root of 987907421 is about 31430.9945913266. The cubic root of 987907421 is about 995.9527824613.

The spelling of 987907421 in words is "nine hundred eighty-seven million, nine hundred seven thousand, four hundred twenty-one".