81245030402 has 4 divisors (see below), whose sum is σ = 121867545606. Its totient is φ = 40622515200.

The previous prime is 81245030381. The next prime is 81245030407. The reversal of 81245030402 is 20403054218.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 76175448001 + 5069582401 = 275999^2 + 71201^2 .

It is not an unprimeable number, because it can be changed into a prime (81245030407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20311257599 + ... + 20311257602.

Almost surely, 2^81245030402 is an apocalyptic number.

81245030402 is a deficient number, since it is larger than the sum of its proper divisors (40622515204).

81245030402 is a wasteful number, since it uses less digits than its factorization.

81245030402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40622515203.

The product of its (nonzero) digits is 7680, while the sum is 29.

The spelling of 81245030402 in words is "eighty-one billion, two hundred forty-five million, thirty thousand, four hundred two".