87978069 has 10 divisors (see below), whose sum is σ = 131424150. Its totient is φ = 58651992.

The previous prime is 87978061. The next prime is 87978097. The reversal of 87978069 is 96087978.

It can be written as a sum of positive squares in only one way, i.e., 82628100 + 5349969 = 9090^2 + 2313^2 .

It is not a de Polignac number, because 87978069 - 2³ = 87978061 is a prime.

It is a super-2 number, since 2×87978069² = 15480281249937522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87978061) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 542994 + ... + 543155.

It is an arithmetic number, because the mean of its divisors is an integer number (13142415).

Almost surely, 2^87978069 is an apocalyptic number.

It is an amenable number.

87978069 is a deficient number, since it is larger than the sum of its proper divisors (43446081).

87978069 is a wasteful number, since it uses less digits than its factorization.

87978069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086161 (or 1086152 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The square root of 87978069 is about 9379.6625205814. The cubic root of 87978069 is about 444.7590649626.

The spelling of 87978069 in words is "eighty-seven million, nine hundred seventy-eight thousand, sixty-nine".