78213402 has 24 divisors (see below), whose sum is σ = 170966484. Its totient is φ = 25839744.

The previous prime is 78213391. The next prime is 78213427. The reversal of 78213402 is 20431287.

It can be written as a sum of positive squares in 2 ways, for example, as 70711281 + 7502121 = 8409^2 + 2739^2 .

It is a super-2 number, since 2×78213402² = 12234672504827208, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17193 + ... + 21260.

Almost surely, 2^78213402 is an apocalyptic number.

78213402 is an abundant number, since it is smaller than the sum of its proper divisors (92753082).

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

78213402 is a wasteful number, since it uses less digits than its factorization.

78213402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38574 (or 38571 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 78213402 is about 8843.8341232748. The cubic root of 78213402 is about 427.6551688693.

Adding to 78213402 its reverse (20431287), we get a palindrome (98644689).

The spelling of 78213402 in words is "seventy-eight million, two hundred thirteen thousand, four hundred two".